[docs] Explicitly close a tags

Authored by: bashonly

README.md

@@ -192,7 +192,7 @@ If you [installed with pip](https://github.com/yt-dlp/yt-dlp/wiki/Installation#w
 
 For other third-party package managers, see [the wiki](https://github.com/yt-dlp/yt-dlp/wiki/Installation#third-party-package-managers) or refer their documentation
 
-<a id="update-channels"/>
+<a id="update-channels"></a>
 
 There are currently three release channels for binaries: `stable`, `nightly` and `master`.
 
@@ -1290,7 +1290,7 @@ To summarize, the general syntax for a field is:
 
 Additionally, you can set different output templates for the various metadata files separately from the general output template by specifying the type of file followed by the template separated by a colon `:`. The different file types supported are `subtitle`, `thumbnail`, `description`, `annotation` (deprecated), `infojson`, `link`, `pl_thumbnail`, `pl_description`, `pl_infojson`, `chapter`, `pl_video`. E.g. `-o "%(title)s.%(ext)s" -o "thumbnail:%(title)s\%(title)s.%(ext)s"`  will put the thumbnails in a folder with the same name as the video. If any of the templates is empty, that type of file will not be written. E.g. `--write-thumbnail -o "thumbnail:"` will write thumbnails only for playlists and not for video.
 
-<a id="outtmpl-postprocess-note"/>
+<a id="outtmpl-postprocess-note"></a>
 
 **Note**: Due to post-processing (i.e. merging etc.), the actual output filename might differ. Use `--print after_move:filepath` to get the name after all post-processing is complete.
 

yt_dlp/networking/common.py

@@ -445,7 +445,7 @@ class Request:
 
     @headers.setter
     def headers(self, new_headers: Mapping):
-        """Replaces headers of the request. If not a CaseInsensitiveDict, it will be converted to one."""
+        """Replaces headers of the request. If not a HTTPHeaderDict, it will be converted to one."""
         if isinstance(new_headers, HTTPHeaderDict):
             self._headers = new_headers
         elif isinstance(new_headers, Mapping):