Missing match_only_text field mapping.

## 🐛 Missing type

The `match_only_text` field mapping is missing. See [documentation](https://www.elastic.co/guide/en/elasticsearch/reference/current/text.html#match-only-text-field-type) and  https://github.com/elastic/elasticsearch/pull/66172

Found in https://github.com/elastic/elasticsearch-java/issues/208