Progress bars & Overlays

[rm-dr]

trafficstars

Generalizing #164, it would be great to have a way to add "overlays" to vhs recordings.

This would allow for...

• Verbose key names (As in #164)
• Progress bars (It's not always clear where a gif begins and ends, especially in a README)
• Emulated window frames and backgrounds, like carbon

[adriens]

I 🗳️ for "Emulated window frames and backgrounds, l"

[maaslalani]

This is a fantastic idea! We definitely want to add window frames + backgrounds and it would be really cool to have key overlays for tutorials.

[rm-dr]

This is pretty easy to pull off with a few extra ffmpeg filters, especially with static images:

https://user-images.githubusercontent.com/96270320/204033970-6ffc1f97-bb03-4f28-8cfa-6f3307d90f39.mp4

GIFs turn out pretty ugly, though, thanks to their limited palette

[adriens]

This is like a carbon ...but :100: :muscle: :weight_lifting: :1st_place_medal:

[rm-dr]

I'm almost ready to submit a PR for static image frames.

A few questions before I do so:

1. I've added Set ImageFrame <file> and Set FrameSize <number> settings. Should I keep these as settings, or should I make them standalone keywords?
2. I'd like to update README.md with an example, but the gifs there are all linked to stuff.charm.sh. Wouldn't it be better to have those directly linked to the repo, so that contributors that can't access stuff.charm.sh (like me) can add demos too? Maybe that's another issue.