synchronize with gamma (vearch#260)

Co-authored-by: xiedabin <[email protected]>

Merge pull request vearch#231 from zcdb/master

Update links in known users in README.md

v0.3.1 (vearch#170)

1. Support real time HNSW index
2. Support binary index
3. Support IVFFLAT index
4. Fix bugs

version v0.3.0