Remove the deprecated name attribute on HTML anchor elements (#1870)

* Remove the deprecated name attribute on HTML anchor elements

Fixes: #1790
Signed-off-by: Johannes Marbach <n0-0ne+github@mailbox.org>

* Add changelog

* Update content/client-server-api/modules/instant_messaging.md

Co-authored-by: Travis Ralston <travpc@gmail.com>

* Update content/client-server-api/modules/instant_messaging.md

Co-authored-by: Travis Ralston <travpc@gmail.com>

* Update changelogs/client_server/newsfragments/1870.deprecation

* Rename 1870.deprecation to 1870.removal

---------

Signed-off-by: Johannes Marbach <n0-0ne+github@mailbox.org>
Co-authored-by: Travis Ralston <travpc@gmail.com>
Co-authored-by: Hubert Chathi <hubertc@matrix.org>

changelogs/client_server/newsfragments/1870.removal

@@ -0,0 +1 @@
+Remove the deprecated name attribute on HTML anchor elements as per [MSC4159](https://github.com/matrix-org/matrix-spec-proposals/pull/4159).

content/client-server-api/modules/instant_messaging.md

@@ -74,7 +74,7 @@ the tag.
 | Tag    | Permitted Attributes                                                                                                                       |
 |--------|--------------------------------------------------------------------------------------------------------------------------------------------|
 | `span` | `data-mx-bg-color`, `data-mx-color`, `data-mx-spoiler` (see [spoiler messages](#spoiler-messages)), `data-mx-maths` (see [mathematical messages](#mathematical-messages)) |
-| `a`    | `name`, `target`, `href` (provided the value is not relative and has a scheme matching one of: `https`, `http`, `ftp`, `mailto`, `magnet`) |
+| `a`    | `target`, `href` (provided the value is not relative and has a scheme matching one of: `https`, `http`, `ftp`, `mailto`, `magnet`)         |
 | `img`  | `width`, `height`, `alt`, `title`, `src` (provided it is a [Matrix Content (`mxc://`) URI](#matrix-content-mxc-uris))                      |
 | `ol`   | `start`                                                                                                                                    |
 | `code` | `class` (only classes which start with `language-` for syntax highlighting)                                                                |