Fixed clone URL of Django git repository.
Fixed tiny commit style inconsistency in committing code documentation.
Fixed #23354 -- Documented that ModelChoiceField to_field_name should be a unique field.

Thanks Keryn Knight for the suggestion.
Documented --database option for migrate.

Thanks Mike O'Connor for the reporty.
Fixed #13749 -- Added link from admin site to front-end site.

Thanks romankrv for the suggestion.
Fixed #23357 -- Added small int introspection support to MySQL backend.

In the MySQL backend, updated the can_introspect_small_integer feature
flag to True. In data_types_reverse, map FIELD_TYPE.SHORT to a
SmallIntegerField. Added test to verify introspecting SmallIntegerFields
and fixed existing tests influenced by this change.
Fixed #23349 -- Clarified details about RunPython's apps argument.
Removed an unused import.