Docs: add v6 in versions page (twbs#42040)

Author: julien-deramond

site/data/docs-versions.yml

@@ -36,7 +36,7 @@
 
 - group: v4.x
   baseurl: 'https://getbootstrap.com/docs'
-  description: 'Our previous major release with its minor releases. Last update was v4.6.2.'
+  description: 'Every minor release from v4 is listed below. Last update was v4.6.2.'
   versions:
     - '4.0'
     - '4.1'
@@ -54,3 +54,9 @@
     - '5.1'
     - '5.2'
     - '5.3'
+
+- group: v6.x
+  baseurl: 'https://getbootstrap.com/docs'
+  description: 'Upcoming major release. First release will be v6.0.'
+  versions:
+    - '6.0'

site/src/pages/docs/versions.astro

@@ -15,7 +15,7 @@ function getVersionsSortedDesc<TKey extends string, TVersions extends Record<TKe
 
 <SingleLayout
   title="Versions"
-  description="An appendix of hosted documentation for nearly every release of Bootstrap, from v1 through v5."
+  description="An appendix of hosted documentation for nearly every release of Bootstrap, from v1 through v6."
 >
   <div class="row">
     {