data dictionary should better explain the difference between fantasy_player_id and fantasy_id

[tanho63]

We have two sets of similar-looking player IDs generated via different methods, which causes some confusion e.g. fantasy_player_id vs fantasy_id.

It would be good if the data dictionary did a better job explaining where the IDs come from (nfl json source vs parsing play descriptions) and what the differences are (including/excluding non-plays e.g. penalties or whatever else)

Original discord convo: https://discord.com/channels/789805604076126219/789817459212812289/1147612381883666512