video: Disable intro by default

video_writer: Implement intro screen (VIII)

video: Make body color lighter

video: Make watermark less visible

video_writer: Fix code body ignoring configured colors

video_writer: Drop ignored alpha channel

video_writer: Implement watermarks (VIII)

video_writer: Read all settings from TOML config (VIII)

video_writer: Split frame renderer into a separate class

video_writer: Move into separate module and add config argument

video_writer: Bump default FPS to 1.5

video_writer: Change variable section split to 1/4 and 3/4

video_writer: Render other variables and tweak sizes (VII)

data: VarHistory: Save other history data as a list of tuples

data: VarHistory: Only include variables from the same function