Updated Insiders changelog and blog plugin documentation

docs/setup/setting-up-a-blog.md

@@ -294,6 +294,42 @@ The following configuration options are available for posts:
               post_excerpt: required
         ```
 
+[`post_excerpt_max_authors`](#+blog.post_excerpt_max_authors){ #+blog.post_excerpt_max_authors }
+
+:   :octicons-milestone-24: Default: `1` – This option specifies the number of
+    authors rendered in post excerpts. While each post may be written by
+    multiple authors, this setting allows to limit the display to just a few or
+    even a single author, or disable authors in excerpts altogether:
+
+    === "Render up to 2 authors in excerpts"
+
+        ``` yaml
+        plugins:
+          - blog:
+              post_excerpt_max_authors: 2
+        ```
+
+    === "Disable authors in excerpts"
+
+        ``` yaml
+        plugins:
+          - blog:
+              post_excerpt_max_authors: 0
+        ```
+
+[`post_excerpt_max_categories`](#+blog.post_excerpt_max_categories){ #+blog.post_excerpt_max_categories }
+
+:   :octicons-milestone-24: Default: `5` – This option specifies the number of
+    categories rendered in post excerpts. While each post may be assigned to
+    multiple categories, the [built-in blog plugin] can be instructed to only
+    show the first `n` categories to keep it short and concise:
+
+    ``` yaml
+    plugins:
+      - blog:
+          post_excerpt_max_categories: 5
+    ```
+
 [`post_excerpt_separator`](#+blog.post_excerpt_separator){ #+blog.post_excerpt_separator }
 
 :   :octicons-milestone-24: Default: `<!-- more -->` – This option specifies
@@ -634,6 +670,18 @@ The following configuration options are available for index pagination:
 
   [paginate]: https://pypi.org/project/paginate/
 
+[`pagination_keep_content`](#+blog.pagination_keep_content){ #+blog.pagination_keep_content }
+
+:   :octicons-milestone-24: Default: `false` – This option specifies whether
+    paginated index pages should inherit the custom content from the index
+    page, i.e. the content of `blog/index.md`:
+
+    ``` yaml
+    plugins:
+      - blog:
+          pagination_keep_content: true
+    ```
+
 #### Authors
 
 The following configuration options are available for author info:
@@ -667,29 +715,6 @@ The following configuration options are available for author info:
     The path must be defined relative to [`blog_dir`][this is configurable].
     Also see the section on [adding authors].
 
-[`authors_in_excerpt`](#+blog.authors_in_excerpt){ #+blog.authors_in_excerpt }
-
-:   :octicons-milestone-24: Default: `1` – This option specifies the number of
-    authors rendered in post excerpts. While each post may be written by
-    multiple authors, this setting allows to limit the display to just a few or
-    even a single author, or disable authors in excerpts altogether:
-
-    === "Render up to 2 authors in excerpts"
-
-        ``` yaml
-        plugins:
-          - blog:
-              authors_in_excerpt: 2
-        ```
-
-    === "Disable authors in excerpts"
-
-        ``` yaml
-        plugins:
-          - blog:
-              authors_in_excerpt: 0
-        ```
-
   [adding authors]: #adding-authors
 
 #### Drafts
@@ -1198,6 +1223,59 @@ nav:
 
 ## Customization
 
+### Custom index pages
+
+[:octicons-tag-24: insiders-4.24.0][Insiders] ·
+:octicons-beaker-24: Experimental
+
+If you want to add custom content to automatically generated [archive] and 
+[category] indexes, e.g. to add a category description prior to the list of
+posts, you can manually create the category page in the same location where
+the [built-in blog plugin] would create it:
+
+``` sh
+.
+├─ docs/
+│  └─ blog/
+│     ├─ category/
+│     │  └─ hello.md #(1)!
+│     ├─ posts/
+│     └─ index.md
+└─ mkdocs.yml
+```
+
+1.  The easiest way is to first [add the category] to the blog post, then take
+    the URL generated by the [built-in blog plugin] and create the file at the
+    corresponding location in the [`blog_dir`][this is configurable] folder.
+
+    Note that the shown directory listing is based on the default configuration.
+    If you specify different values for the following options, be sure to adjust
+    the path accordingly:
+
+    - [`blog_dir`][this is configurable]
+    - [`categories_url_format`][categories_url_format]
+    - [`categories_slugify`][categories_slugify]
+
+You can now add arbitrary content to the newly created file, or set specific
+page properties for this page via front matter, e.g. to change the
+[page description]:
+
+``` yaml
+---
+description: Nullam urna elit, malesuada eget finibus ut, ac tortor.
+---
+
+# Hello
+...
+```
+
+All posts belonging to the category will be automatically appended.
+
+  [add the category]: #adding-categories
+  [page description]: ../reference/index.md#setting-the-page-description
+  [categories_url_format]: #+blog.categories_url_format
+  [categories_slugify]: #+blog.categories_slugify
+
 ### Overriding templates
 
 The [built-in blog plugin] is built on the same basis as Material for MkDocs,