search filter for videos with subtitle

[Reise-Reise]

Describe the problem to be solved

You can add subtitles to videos. But it is not yet possible to find such videos easily.

Users should have the option to only displaying videos with subtitles when searching for a video. This would make Peertube more accessible, especially for the hearing impaired.

Describe the solution you would like

Inside the search filter section (below the "Language" dropdown menu) a checkbox:

[ ] only videos with subtitle

default setting: unchecked

The language of the subtitle should be respected (there might be more than one) if a language has been selected in the "Language" dropdown menu.