* docs: update csharp connector status

* docs: fix csharp ws bulk pulling

* docs: clarify database param is optional to websocket dsn

* docs: fix java connector mistake

* fix: a few typos

* fix: many typos

* docs: java connector support subscription over websocket

* fix: update 3.0 connector feature matrix

feature: tag scan group and slimit

enh: unify error msg for no disk space

enh: comment off unused error codes in sync and wal

change learner config format

filter voter when agree upon

feat: support log slow query by default

enh: ignore single row null data type validation

remove null pointer

enh: support user passwd version

refactor: do some internal refactor and add the sample code.

enhance: error code refactor

fix/block-check-to-async-check

fix(stream): set the correct start offset for stream task.

fix: update commit index from heartbeat on  learner in the same way as on follower