Bump version to 5.0.0-alpha1 (#29925)

Also add v4.5.0 in versions and keep README.md pointing to v4.5.0 so that there are no broken stuff.

site/content/docs/4.3/_index.html

@@ -1,5 +0,0 @@
----
-layout: redirect
-sitemap_exclude: true
-redirect: "/docs/4.3/getting-started/introduction/"
----

site/content/docs/5.0/_index.html

@@ -0,0 +1,5 @@
+---
+layout: redirect
+sitemap_exclude: true
+redirect: "/docs/5.0/getting-started/introduction/"
+---

site/content/docs/5.0/about/overview.md

@@ -5,7 +5,7 @@ description: Learn more about the team maintaining Bootstrap, how and why the pr
 group: about
 aliases:
   - "/about/"
-  - "/docs/4.3/about/"
+  - "/docs/5.0/about/"
 ---
 
 ## Team

site/content/docs/5.0/components/alerts.md

@@ -5,7 +5,7 @@ description: Provide contextual feedback messages for typical user actions with
 group: components
 aliases:
   - "/components/"
-  - "/docs/4.3/components/"
+  - "/docs/5.0/components/"
 toc: true
 ---
 

site/content/docs/5.0/content/reboot.md

@@ -3,7 +3,7 @@ layout: docs
 title: Reboot
 description: Reboot, a collection of element-specific CSS changes in a single file, kickstart Bootstrap to provide an elegant, consistent, and simple baseline to build upon.
 group: content
-aliases: "/docs/4.3/content/"
+aliases: "/docs/5.0/content/"
 toc: true
 ---
 

site/content/docs/5.0/customize/overview.md

@@ -4,7 +4,7 @@ title: Customize
 description: Learn how to theme, customize, and extend Bootstrap with Sass, a boatload of global options, an expansive color system, and more.
 group: customize
 toc: false
-aliases: "/docs/4.3/customize/"
+aliases: "/docs/5.0/customize/"
 sections:
   - title: Sass
     description: Utilize our source Sass files to take advantage of variables, maps, mixins, and functions.

site/content/docs/5.0/extend/approach.md

@@ -4,7 +4,7 @@ title: Approach
 description: Learn about the guiding principles, strategies, and techniques used to build and maintain Bootstrap so you can more easily customize and extend it yourself.
 group: extend
 aliases:
-  - "/docs/4.3/extend/"
+  - "/docs/5.0/extend/"
 ---
 
 While the getting started pages provide an introductory tour of the project and what it offers, this document focuses on _why_ we do the things we do in Bootstrap. It explains our philosophy to building on the web so that others can learn from us, contribute with us, and help us improve.

site/content/docs/5.0/forms/overview.md

@@ -4,7 +4,7 @@ title: Forms
 description: Examples and usage guidelines for form control styles, layout options, and custom components for creating a wide variety of forms.
 group: forms
 toc: true
-aliases: "/docs/4.3/forms/"
+aliases: "/docs/5.0/forms/"
 sections:
   - title: Form control
     description: Style textual inputs and textareas with support for multiple states.

site/content/docs/5.0/getting-started/contents.md

@@ -147,7 +147,7 @@ bootstrap/
 ├── site/
 │   └──content/
 │      └── docs/
-│          └── 4.3/
+│          └── 5.0/
 │              └── examples/
 ├── js/
 └── scss/

site/content/docs/5.0/getting-started/introduction.md

@@ -4,7 +4,7 @@ title: Introduction
 description: Get started with Bootstrap, the world's most popular framework for building responsive, mobile-first sites, with BootstrapCDN and a template starter page.
 group: getting-started
 aliases:
-  - "/docs/4.3/getting-started/"
+  - "/docs/5.0/getting-started/"
   - "/docs/getting-started/"
   - "/getting-started/"
 toc: true