Add OpenHistoricalMap as a destination for edits, adding a OpenHistoricalMap (OHM) option to the filter from #18. Checks should be added if OHM is being added for start_date missing errors and end_date missing warnings.
Possible: Add to OpenHistoricalMap automatically (if a user opts-in) if start_date is added to an element.
Add OpenHistoricalMap as a destination for edits, adding a OpenHistoricalMap (OHM) option to the filter from #18. Checks should be added if OHM is being added for `start_date` missing errors and `end_date` missing warnings.
Possible: Add to OpenHistoricalMap automatically (if a user opts-in) if `start_date` is added to an element.