update contributing docs

Contributing.md

@@ -3,11 +3,12 @@
 
 Want to contribute to Slate? That would be awesome!
 
-- [Opening Issues](#opening-issues)
-- [Pull Requests](#pull-requests)
+- [Reporting Bugs](#reporting-bugs)
+- [Asking Questions](#asking-questions)
+- [Submitting Pull Requests](#pull-requests)
 - [Running Tests](#running-tests)
 - [Running Examples](#running-examples)
-- [Browser Support](#browser-support)
+- [Adding Browser Support](#browser-support)
 
 
 ## Reporting Bugs
@@ -23,8 +24,12 @@ Here's a [JSFiddle template for Slate](https://jsfiddle.net/2zokvrvt/4/) to get
 
 Questions are very welcome :smile:! Previous questions that folks have asked are tagged with a [`question`](https://github.com/ianstormtaylor/slate/issues?q=is%3Aissue+is%3Aclosed+label%3Aquestion) label, so before opening a new issue double-check that someone hasn't asked it before. But if you don't see anything, or if you're not sure if it's the same, err on the side of asking!
 
+We've also got a [Slate Slack team](https://slate-slack.herokuapp.com) where you can ask questions and get answers from other people using Slate:
 
-## Pull Requests
+[![](./docs/images/slack.png)](https://slate-slack.herokuapp.com)
+
+
+## Submitting Pull Requests
 
 All pull requests are super welcomed and greatly appreciated! Easy issues are marked with an [`easy-one`](https://github.com/ianstormtaylor/slate/issues?q=is%3Aopen+is%3Aissue+label%3Aeasy-one) label if you're looking for a simple place to get familiar with the code base.
 
@@ -51,9 +56,7 @@ And to run the linter:
 npm run lint
 ```
 
-Or you can run both with `make check`, which is what is run by default.
-
-If you need to debug something, you can add a `debugger` line to the source, and then run `npm test --debug`. Or, if you only want to run a specific test or tests, you can run `npm test --fgrep "match thisstring"` flag which will filter the tests being run.
+If you need to debug something, you can add a `debugger` line to the source, and then run `npm test debug`. Or, if you only want to run a specific test or tests, you can run `npm test -- --fgrep "match this string"` flag which will filter the tests being run.
 
 To keep the source rebuilding on every file change, you need to run an additional watching command:
 
@@ -67,7 +70,7 @@ npm run dist:watch
 Check out the [Examples readme](./examples) to see how to get the examples running locally!
 
 
-## Browser Support
+## Adding Browser Support
 
 Slate aims to targeted all of the modern browsers, and eventually the modern mobile platforms. Right now browser support is limited to the latest versions of [Chrome](https://www.google.com/chrome/browser/desktop/), [Firefox](https://www.mozilla.org/en-US/firefox/new/), and [Safari](http://www.apple.com/safari/), but if you are interested in adding support for another modern platform, that is welcomed!