Added able to pause/resume recording, default filename with timestamp…

[acrossoffwest]

Added few features:

1. Pause and resume record(ctrl+z)
2. Start recording into new file(ctrl + \)
3. Also if user didn't specified filename it will generated with timestamp(example: movie-20210828202653.mov).

I hope it will useful for somebody.

Sorry for not using PR guideline, you could delete if these changes unnecessary.

[matthutchinson]

Thanks for this submission! I made some big changes recently - I'll take care of your PR probably by creating another one - rebased off master.

[matthutchinson]

Closing for now, I've released v0.0.8 with generated timestamps in the filename and pause/resume (via Ctrl+z).

I wasn't able to get Ctrtl+\ working to stop and start recording with a new filename. Please open a new PR if you want to add this.