Update info about versioning index files (#46309)

content/contributing/writing-for-github-docs/using-yaml-frontmatter.md

@@ -71,12 +71,12 @@ versions:
   ghes: '*'
 ```
 
-You can also version a page for a range of releases. This would version the page for {% data variables.product.prodname_dotcom_the_website %}, and {% data variables.product.prodname_ghe_server %} versions 2.22 and 3.0 only:
+You can also version a page for a range of releases. This would version the page for {% data variables.product.prodname_dotcom_the_website %}, and {% data variables.product.prodname_ghe_server %} versions 3.1 and 3.2 only:
 
 ```yaml
 versions:
   fpt: '*'
-  ghes: '>=2.22 <3.1'
+  ghes: '>=3.1 <3.3'
 ```
 
 ### `redirect_from`
@@ -303,7 +303,7 @@ When adding a new article, make sure the filename is a [kebab-cased](https://en.
 
 ## Index pages
 
-Index pages are the Table of Contents files for the docs site. Every product, category, and map topic subdirectory has an `index.md` that serves as the landing page. Each `index.md` must contain a `children` frontmatter property with a list of relative links to the child pages of the product, category, or map topic.
+Index pages are the table of contents files for the Docs site. Every product, category, and map topic subdirectory has an `index.md` file that provides an overview of the content and links to every child article. Each `index.md` must contain a `children` frontmatter property with a list of relative links to the child pages of the product, category, or map topic. Index pages require a `versions` frontmatter property, and the actual value will be computed at runtime based on the versions of children articles.
 
 {% note %}
 

content/contributing/writing-for-github-docs/versioning-documentation.md

@@ -77,7 +77,9 @@ Versioning for {% data variables.product.prodname_ghe_managed %} uses the `githu
 
 ## Versioning in the YAML frontmatter
 
-You can use the `versions` property within the file's frontmatter to define which products an entire page applies to. For example, the following YAML frontmatter will version an article for {% data variables.product.prodname_ghe_server %} 2.20 and above and Free, Pro, or Team.
+You can use the `versions` property within a file's frontmatter to define which products an article will appear for. Index files require a `versions` property, but they will be automatically versioned based on the versions of their children.
+
+For example, the following YAML frontmatter will version an article for {% data variables.product.prodname_ghe_server %} 2.20 and above and Free, Pro, or Team.
 
 ```yaml
 title: About your personal dashboard
@@ -94,13 +96,13 @@ versions:
   ghes: '*'
 ```
 
-You can also version a page for a range of releases. The following example will version the page for {% data variables.product.prodname_dotcom_the_website %}, and {% data variables.product.prodname_ghe_server %} versions 2.22 and 3.0 only:
+You can also version a page for a range of releases. The following example will version the page for {% data variables.product.prodname_dotcom_the_website %}, and {% data variables.product.prodname_ghe_server %} versions 3.1 and 3.2 only:
 
 ```yaml
 versions:
   fpt: '*'
   ghec: '*'
-  ghes: '>=2.22 <3.1'
+  ghes: '>=3.1 <3.3'
 ```
 
 ## Versioning with Liquid conditional operators