Update docs

Author: snejus

docs/changelog.rst

@@ -80,6 +80,9 @@ Bug fixes
   plural field names. :bug:`6483`
 - :doc:`plugins/fetchart`: Error when a configured source does not exist or
   sources configuration is empty. :bug:`6336`
+- :doc:`plugins/rewrite` :doc:`plugins/advancedrewrite`: Fix rewriting
+  multi-valued fields such as ``genres`` by applying rules to each matching list
+  entry. :bug:`6515`
 
 For plugin developers
 ~~~~~~~~~~~~~~~~~~~~~

docs/plugins/advancedrewrite.rst

@@ -28,6 +28,9 @@ replace a single field:
     advancedrewrite:
       - artist ODD EYE CIRCLE: 이달의 소녀 오드아이써클
 
+As with :doc:`/plugins/rewrite`, simple rules applied to a multi-valued field
+rewrite only the matching list entries.
+
 The advanced syntax consists of a query to match against, as well as a map of
 replacements to apply. For example, to credit all songs of ODD EYE CIRCLE before
 2023 to their original group name, you can use the following rule:

docs/plugins/rewrite.rst

@@ -30,6 +30,15 @@ might use:
     rewrite:
         artist .*jimi hendrix.*: Jimi Hendrix
 
+Rules also apply to matching elements in multi-valued fields. For example, this
+rewrites the ``rock`` entry in ``genres`` while leaving other genre values
+unchanged:
+
+::
+
+    rewrite:
+        genres rock: Classic Rock
+
 As a convenience, the plugin applies patterns for the ``artist`` field to the
 ``albumartist`` field as well. (Otherwise, you would probably want to duplicate
 every rule for ``artist`` and ``albumartist``.)