Integrate in OS right click context menu

[isneezy]

• [ x ] I have searched the issues of this repository and believe that this is not a duplicate.

Expected Behavior

When navigating in a file explorer, when user press right click on top of a video file, an option to download subtitle with caption should appear

Current Behavior

Now we have to always open caption and drag and drop video file into it. sometimes it is a very tedious task.

Your Environment

Tech	Version
app version	2.0.1_amd64
OS	elementary OS
etc