### _Why are the changes needed?_
This PR changes the doc authority from Kent to Apache Kyuubi Community. Meanwhile, the footnotes for copyright/license are also simplified.
### _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#3824 from yaooqinn/autority.
Closes#3824
fc25156a [Kent Yao] [DOCS] Authority of the documentation belongs to the community
Authored-by: Kent Yao <yao@apache.org>
Signed-off-by: fwang12 <fwang12@ebay.com>