Documentation needs

- trials table has "goCue_start_time_raw_time" (Should be renamed as "GoCue_raw_time")
- document these fields:
- start_time
- delay_start_time
- goCue_start_time (should rename to goCue)
- choice_time
- reward_outcome_time (should rename to choice_outcome_time)
- reward_time
- stop_time

We need to document that df_fib, df_events have "raw_timestamps" and "timestamps" and that the "raw_timestamps" are what the harp data has.

Need to rename these fields:

1. goCue_starttime should be renamed to 'goCue'
2. reward_outcome_time should be renamed to choice_outcome_time.