Add video mappings to ruleset

The plan is to have a section like:

videos:
  - type: INTRO
    file: ANIMS/INTRO.VID
  - type: OUTRO
    file: ANIMS/OUTRO.VID

etc.

These videos would need to be self-contained (have both audio and video
in the file, ala TFTD).
If there is none defined in the ruleset, we can then fallback to the ufo
w/hardcoded audio cues