<!--
Thanks for sending a pull request!
Here are some tips for you:
1. If this is your first time, please read our contributor guidelines: https://kyuubi.readthedocs.io/en/latest/community/contributions.html
2. If the PR is related to an issue in https://github.com/apache/incubator-kyuubi/issues, add '[KYUUBI #XXXX]' in your PR title, e.g., '[KYUUBI #XXXX] Your PR title ...'.
3. If the PR is unfinished, add '[WIP]' in your PR title, e.g., '[WIP][KYUUBI #XXXX] Your PR title ...'.
-->
### _Why are the changes needed?_
<!--
Please clarify why the changes are needed. For instance,
1. If you add a feature, you can talk about the use case of it.
2. If you fix a bug, you can clarify why it is a bug.
-->
Make release docs better.
### _How was this patch tested?_
Not need.
Closes#1292 from ulysses-you/refine-release.
Closes#1292
fb467563 [ulysses-you] fork and clone
b2418d1d [ulysses-you] mailing list
aa31567b [ulysses-you] refine
Authored-by: ulysses-you <ulyssesyou18@gmail.com>
Signed-off-by: Cheng Pan <chengpan@apache.org>
275d0bd4eb