docs: Reword documentation of playlist plugin's relative_to option
@@ -32,6 +32,7 @@ other configuration options are:
- **playlist_dir**: Where to read playlist files from.
Default: The current working directory (i.e., ``'.'``).
- **relative_to**: Interpret paths in the playlist files relative to a base
- directory. It is also possible to set it to ``playlist`` to use the
- playlist's parent directory as base directory.
+ directory. Instead of setting it to a fixed path, it is also possible to
+ set it to ``playlist`` to use the playlist's parent directory or to
+ ``library`` to use the library directory.
Default: ``library``
