* Support elastic search for code search
* Finished elastic search implementation and add some tests
* Enable test on drone and added docs
* Add new fields to elastic search
* Fix bug
* remove unused changes
* Use indexer alias to keep the gitea indexer version
* Improve codes
* Some code improvements
* The real indexer name changed to xxx.v1
Co-authored-by: zeripath <art27@cantab.net>
