### _Why are the changes needed?_
Add debugging instructions for Flink engine.
### _How was this patch tested?_
- [ ] Add some test cases that check the changes thoroughly including negative and positive cases if possible
- [ ] Add screenshots for manual tests if appropriate
- [x] [Run test](https://kyuubi.apache.org/docs/latest/develop_tools/testing.html#running-tests) locally before make a pull request
Closes#2098 from SteNicholas/KYUUBI-2089.
Closes#2089
08189b85 [SteNicholas] [KYUUBI #2089] Add debugging instructions for flink engine
Authored-by: SteNicholas <programgeek@163.com>
Signed-off-by: Kent Yao <yao@apache.org>