Correct description of required model-output subdirectory structure

[annakrystalli]

Currently the documentation on the expected model-output subdirectory structure on page /user-guide/model-output.html is incorrect

It show the required structure to erroneously be:

team1-modela
   <round-id1>.csv (or parquet, etc)
   <round-id2>.csv (or parquet, etc)
team1-modelb
   <round-id1>.csv (or parquet, etc)
team2-modela
   <round-id1>.csv (or parquet, etc)

when it should be:

team1-modela
   <round-id1>-<model_id>.csv (or parquet, etc)
   <round-id2>-<model_id>.csv (or parquet, etc)
team1-modelb
   <round-id1>-<model_id>.csv (or parquet, etc)
team2-modela
   <round-id1>-<model_id>.csv (or parquet, etc)

[annakrystalli]

This might also be a good place to re-iterate that model_id = team_abbr-model_abbr.

[mmkerr]

Resolved with PR #119