Added doc for switching elasticsearch to infinity (#3370)
### What problem does this PR solve?
Added doc for switching elasticsearch to infinity
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
- [x] Documentation Update
### What problem does this PR solve?
Integration with Infinity
- Replaced ELASTICSEARCH with dataStoreConn
- Renamed deleteByQuery with delete
- Renamed bulk to upsertBulk
- getHighlight, getAggregation
- Fix KGSearch.search
- Moved Dealer.sql_retrieval to es_conn.py
### Type of change
- [x] Refactoring