Sitcom-simulator

Biggest feature drop yet!

New video settings:
- Video speed multiplier
- Support for landscape videos
- Images now have a pan-and-zoom effect applied to them, with an option to disable if desired
- More robust character selection algorithm
- More robust audio balancing between character voices and background music.

The number of sign-in requests to fakeyou has been reduced considerably.

You can now sign into fakeyou for faster audio generation (~3x faster, if not even more). This is done by setting FAKEYOU_USERNAME and FAKEYOU_PASSWORD as environment variables.

The style of video captions can now be customized between box background or text shadow. You can do so via `--text-shadow` on the command line, or with more detailed options in the python API

Adds the ability to customize the instructions given to ChatGPT during script generation and character extraction.