[Feature request] Add manual download button

[mylogon341]

Tl;dr Add a manual download button

With bigger or older yt channels, they might have several hundred videos. When adding them you don't always want all the videos (especially if you're a long time viewer) so when adding the source, you set the download threshold to 1 week. However, you look through their backlog (in the skipped media) and see some videos that you enjoyed in the past and want to fetch ad-hoc. There is currently no way to do this (other than click on the yt link) as the 1 week cut off date in tubesync is gospel. Can you add a 'manual override' button that trumps other checks and just kicks off a download? That'd be nice, I think.

[meeb]

Thanks for the issue. Sounds like a reasonable suggestion, I'll pop it on the wishlist.