What is tween_settings?

I wanted an OBS-friendly way to read/write settings per-scene. I could read/write a file from a path as chosen by the end user, but I could also store the settings per-scene in the scene itself as a source.

I store the data in a JSON format and ensure that the transform of the source is such that it's not visible, by simply setting the size to 0, 0.

This is not 100% done being engineered, but this is how I like it for now.