Ytdl-sub

[FEATURE] `format` plugin to set yt-dlp format easier (714)

Makes setting yt-dlp's `format` field easier by giving it its own documented plugin.

Old:

my_format_preset:
ytdl_options:
format: "best"


New:

my_format_preset:
format: "best"


The old method will still work, so do not worry about updating configs ASAP. However, the option is available to save a few lines :wink:
Docs can be found [here](https://ytdl-sub.readthedocs.io/en/latest/config.html#format).

[BACKEND] Set merge_output_format to file_convert file type (699)

Adds a small optimization to potentially avoid an additional remux by setting yt-dlp's merge output format to the desired format in the `file_convert` plugin (https://ytdl-sub.readthedocs.io/en/latest/config.html#file-convert)

[BACKEND] Plex TV show presets to always convert to mp4 format (701)

Plex and webm do not play well together at this time. To mitigate issues, always convert to mp4 when using any Plex prebuilt preset.

[FEATURE] Support `best` codec type in audio_extract (700)

Adds support to the `audio_extract` plugin (https://ytdl-sub.readthedocs.io/en/latest/config.html#audio-extract) to the following to grab the best audio format available:


audio_extract:
codec: "best"

[DEV] Fix split-by-chapters test (702)

Fixing the split_by_chapters test suite. Also do not make releases for commits with [DEV] in them. If you see this, it didn't work 😅

[FEATURE] Commit message as release notes (695)

Release notes will now contain commit messages. I will do better to provide a more meaningful changelog here