Add GstWebRTC-1.0 docset
Per https://github.com/ptomato/devdocs/issues/14, GstWebRTC is not available in the list of docsets.
Python version: https://lazka.github.io/pgi-docs/GstWebRTC-1.0/index.html
Per https://github.com/ptomato/devdocs/issues/14, GstWebRTC is not available in the list of docsets.
Python version: https://lazka.github.io/pgi-docs/GstWebRTC-1.0/index.html