Update issue templates

.github/ISSUE_TEMPLATE/---core-bug.md

@@ -0,0 +1,35 @@
+---
+name: "\U0001F6A8 Core bug"
+about: A bug that occurs in Slate's core logic, on all platforms
+title: ''
+labels: bug
+assignees: ''
+
+---
+
+**Description**
+A clear and concise description of what the bug is.
+
+**Recording**
+A GIF or video showing the issue happening. (If you don't include this, there's a very good chance your issue will be closed, because it's much too hard to figure out exactly what is going wrong, and it makes maintenance much harder.)
+
+**Sandbox**
+A link to a sandbox where the error can be reproduced. (You can start from the base sandbox here: https://codesandbox.io/s/slate-reproductions-c7gyg or refer to the Slate website too.)
+
+**Steps**
+To reproduce the behavior:
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**Expectation**
+A clear and concise description of what you expected to happen. (Often it's helpful to test out the behavior of other editors like Google Docs, Medium, Notion, etc. to see how they handle the same issue.)
+
+**Environment**
+- Slate Version: [e.g. 0.59]
+- Operating System: [e.g. iOS]
+- Browser: [e.g. Chrome, Safari]
+
+**Context**
+Add any other context about the problem here. (The fastest way to have an issue fixed is to create a pull request with working, tested code and we'll help merge it. Slate is solving a pretty complex problem, and we can't do it without active contributors, so thank you so much for your help!)

.github/ISSUE_TEMPLATE/---feature-request.md

@@ -0,0 +1,20 @@
+---
+name: "\U0001F4E6 Feature request"
+about: An idea or request for new functionality
+title: ''
+labels: feature
+assignees: ''
+
+---
+
+**Problem**
+A clear and concise description of what the problem is. (Eg. I'm always frustrated when [...])
+
+**Solution**
+A clear and concise description of what you want to happen.
+
+**Alternatives**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Context**
+Add any other context about the problem here. (The fastest way to have an issue fixed is to create a pull request with working, tested code and we'll help merge it. Slate is solving a pretty complex problem, and we can't do it without active contributors, so thank you so much for your help!)

.github/ISSUE_TEMPLATE/---improvement.md

@@ -0,0 +1,20 @@
+---
+name: "\U0001F6E0 Improvement"
+about: An improvement to existing functionality
+title: ''
+labels: improvement
+assignees: ''
+
+---
+
+**Problem**
+A clear and concise description of what the problem is. (Eg. I'm always frustrated when [...])
+
+**Solution**
+A clear and concise description of what you want to happen.
+
+**Alternatives**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Context**
+Add any other context about the problem here. (The fastest way to have an issue fixed is to create a pull request with working, tested code and we'll help merge it. Slate is solving a pretty complex problem, and we can't do it without active contributors, so thank you so much for your help!)

.github/ISSUE_TEMPLATE/---platform-bug.md

@@ -0,0 +1,35 @@
+---
+name: "\U0001F5A5 Platform bug"
+about: A bug that occurs in a specific browser or platform
+title: ''
+labels: bug, ⚑ cross platform
+assignees: ''
+
+---
+
+**Description**
+A clear and concise description of what the bug is.
+
+**Recording**
+A GIF or video showing the issue happening. (If you don't include this, there's a very good chance your issue will be closed, because it's much too hard to figure out exactly what is going wrong, and it makes maintenance much harder.)
+
+**Sandbox**
+A link to a sandbox where the error can be reproduced. (You can start from the base sandbox here: https://codesandbox.io/s/slate-reproductions-c7gyg or refer to the Slate website too.)
+
+**Steps**
+To reproduce the behavior:
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**Expectation**
+A clear and concise description of what you expected to happen. (Often it's helpful to test out the behavior of other editors like Google Docs, Medium, Notion, etc. to see how they handle the same issue.)
+
+**Environment**
+- Slate Version: [e.g. 0.59]
+- Operating System: [e.g. iOS]
+- Browser: [e.g. Chrome, Safari]
+
+**Context**
+Add any other context about the problem here. (The fastest way to have an issue fixed is to create a pull request with working, tested code and we'll help merge it. Slate is solving a pretty complex problem, and we can't do it without active contributors, so thank you so much for your help!)

.github/ISSUE_TEMPLATE/core-bug.md

@@ -0,0 +1,35 @@
+---
+name: Core bug
+about: A bug that occurs in Slate's core logic, on all platforms
+title: ''
+labels: bug
+assignees: ''
+
+---
+
+**Description**
+A clear and concise description of what the bug is.
+
+**Recording**
+A GIF or video showing the issue happening. (If you don't include this, there's a very good chance your issue will be closed, because it's much too hard to figure out exactly what is going wrong, and it makes maintenance much harder.)
+
+**Sandbox**
+A link to a sandbox where the error can be reproduced. (You can start from the base sandbox here: https://codesandbox.io/s/slate-reproductions-c7gyg or refer to the Slate website too.)
+
+**Steps**
+To reproduce the behavior:
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**Expectation**
+A clear and concise description of what you expected to happen. (Often it's helpful to test out the behavior of other editors like Google Docs, Medium, Notion, etc. to see how they handle the same issue.)
+
+**Environment**
+- Slate Version: [e.g. 0.59]
+- Operating System: [e.g. iOS]
+- Browser: [e.g. Chrome, Safari]
+
+**Context**
+Add any other context about the problem here. (The fastest way to have an issue fixed is to create a pull request with working, tested code and we'll help merge it. Slate is solving a pretty complex problem, and we can't do it without active contributors, so thank you so much for your help!)

.github/ISSUE_TEMPLATE/platform-bug-report.md

@@ -0,0 +1,35 @@
+---
+name: Platform bug report
+about: A bug that occurs in a specific browser or platform
+title: ''
+labels: bug, ⚑ cross platform
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**Video**
+A GIF or video showing the issue happening. (If you don't include this, there's a very good chance your issue will be closed, because it's much too hard to figure out exactly what is going wrong, and it makes maintenance much harder.)
+
+**Sandbox**
+A link to a sandbox where the error can be reproduced. (You can start from the base sandbox here: https://codesandbox.io/s/slate-reproductions-c7gyg or refer to the Slate website too.)
+
+**Steps to reproduce**
+Steps to reproduce the behavior:
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**Expected behavior**
+A clear and concise description of what you expected to happen. (Often it's helpful to test out the behavior of other editors like Google Docs, Medium, Notion, etc. to see how they handle the same issue.)
+
+**Environment:**
+- Slate Version: [e.g. 0.59]
+- Operating System: [e.g. iOS]
+- Browser: [e.g. Chrome, Safari]
+
+**Additional context**
+Add any other context about the problem here. (The fastest way to have an issue fixed is to create a pull request with working, tested code and we'll help merge it. Slate is solving a pretty complex problem, and we can't do it without active contributors, so thank you so much for your help!)

.github/ISSUE_TEMPLATE/platform-bug.md

@@ -0,0 +1,35 @@
+---
+name: Platform bug
+about: A bug that occurs in a specific browser or platform
+title: ''
+labels: bug, ⚑ cross platform
+assignees: ''
+
+---
+
+**Description**
+A clear and concise description of what the bug is.
+
+**Recording**
+A GIF or video showing the issue happening. (If you don't include this, there's a very good chance your issue will be closed, because it's much too hard to figure out exactly what is going wrong, and it makes maintenance much harder.)
+
+**Sandbox**
+A link to a sandbox where the error can be reproduced. (You can start from the base sandbox here: https://codesandbox.io/s/slate-reproductions-c7gyg or refer to the Slate website too.)
+
+**Steps**
+To reproduce the behavior:
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**Expectation**
+A clear and concise description of what you expected to happen. (Often it's helpful to test out the behavior of other editors like Google Docs, Medium, Notion, etc. to see how they handle the same issue.)
+
+**Environment**
+- Slate Version: [e.g. 0.59]
+- Operating System: [e.g. iOS]
+- Browser: [e.g. Chrome, Safari]
+
+**Context**
+Add any other context about the problem here. (The fastest way to have an issue fixed is to create a pull request with working, tested code and we'll help merge it. Slate is solving a pretty complex problem, and we can't do it without active contributors, so thank you so much for your help!)