Support web links for metadata entries

We show server metadata in the UI. Being able to provide web links for
the metadata entries allows us to provide context links (e.g. link to
documentation, link to file a bug, link to a group).

Make use of the web links for the 'accounts.visibility' metadata to
provide a link to the corresponding documentation.

Release-Notes: skip
Bug: Google b/330836100
Change-Id: I904ca59cd0d080428e13ea13a2540376f1215678
Signed-off-by: Edwin Kempin <ekempin@google.com>
diff --git a/Documentation/rest-api-config.txt b/Documentation/rest-api-config.txt
index b85545a..0cb407e 100644
--- a/Documentation/rest-api-config.txt
+++ b/Documentation/rest-api-config.txt
@@ -2410,6 +2410,8 @@
 metadata entries with the same name may be returned.
 |`value`      |optional|The metadata value.
 |`description`|optional|A description of the metadata.
+|`web_links`  |optional|A list of web links as
+link:rest-api-changes.html#web-link-info[WebLinkInfo] entities.
 |==========================
 
 [[plugin-config-info]]