Shared column schema: espn mbb week rankings schema

Columns shared verbatim across: espn_mbb_week_rankings, espn_nba_week_rankings.

Details

col_name	types	description
league	character	League slug.
season	integer	Season year.
season_type	integer	Season-type id.
week	integer	Week number.
ranking_id	character	ESPN ranking id.
ref	character	$ref URL for the ranked-teams detail.