### _Why are the changes needed?_
The following pictures are removed from master branch, some of them with A-prefix are renamed
```
D docs/imgs/authorization.png
D docs/imgs/ha_failover.png
D docs/imgs/impersonation.png
D docs/imgs/kyuubi.png
D docs/imgs/kyuubi_architecture.png
D docs/imgs/kyuubi_internal.png
D docs/imgs/kyuubi_logo.png
D docs/imgs/kyuubi_logo_gray.png
D docs/imgs/kyuubi_logo_legacy.png
D docs/imgs/kyuubi_logo_red.png
D docs/imgs/kyuubi_logo_white_2.png
D docs/imgs/kyuubi_logo_white_legacy.png
A docs/imgs/logo.png
A docs/imgs/logo_gray_short.png
A docs/imgs/logo_red_short.png
A docs/imgs/logo_white_short.png
```
### _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#3784 from yaooqinn/cleanup.
Closes#3784
66ce11b0 [Kent Yao] [DOCS] Remove unused stale imagine from documentation
Authored-by: Kent Yao <yao@apache.org>
Signed-off-by: Cheng Pan <chengpan@apache.org>
a3935d8b15