Enums not matched in postgraphile.tags.json5
### Summary

Enums are not matched in postgraphile.tags.json5 (though I'm _not_ having the same issue attaching tags via comments)

### Steps to reproduce

1) Create an enum in Postgres
2) Reference said enum in postgraphile.tags.json5 under `class`

### Expected results

Enum will be found and matched

### Actual results

Enum not matched: `WARNING: there were no matches for makePgSmartTagsPlugin rule 14 -  ...`
