docs: Update changelog with audio taglist changes etc

docs/changelog.rst

@@ -69,6 +69,25 @@ v0.20.0 (UNRELEASED)
 
   - Add foundation for trying to re-add multiple output support.
 
+  - Add internal helper for converting GStreamer data types to Python.
+
+  - Move MusicBrainz coverart code out of audio and into local.
+
+  - Reduce scope of audio scanner to just tags + duration. Mtime, uri and min
+    length handling are now outside of this class.
+
+  - Update scanner to operate with milliseconds for duration.
+
+- Add :meth:`mopidy.audio.AudioListener.tags_changed`. Notifies core when new tags
+  are found.
+
+- Add :meth:`mopidy.audio.Audio.get_current_tags` for looking up the current
+  tags of the playing media.
+
+- Move and rename helper for converting tags to tracks.
+
+  - Helper now ignores albums without a name.
+
 - Kill support for visualizers. Feature was originally added as a workaround for
   all the people asking for ncmpcpp visualizer support. And since we could get
   it almost for free thanks to GStreamer. But this feature didn't really ever
@@ -76,6 +95,11 @@ v0.20.0 (UNRELEASED)
   it is in use and will be missed is to go ahead and remove it.
 
 
+**Stream backend**
+
+- Add basic tests for the stream library provider.
+
+
 v0.19.5 (UNRELEASED)
 ====================