[KYUUBI #1844] Add step for generating release notes

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### _Why are the changes needed?_
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### _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

- [ ] [Run test](https://kyuubi.apache.org/docs/latest/develop_tools/testing.html#running-tests) locally before make a pull request

Closes #1864 from yanghua/KYUUBI-1844.

Closes #1844

47d09c3 [yanghua] Address review comments
b5a8bbc [yanghua] [KYUUBI #1844] Add step for generating release notes

Authored-by: yanghua <yanghua1127@gmail.com>
Signed-off-by: ulysses-you <ulyssesyou@apache.org>

Author: yanghua

docs/community/release.md

@@ -184,6 +184,8 @@ git commit -am "[RELEASE] Bump ${RELEASE_VERSION}"
 
 The tag pattern is `v${RELEASE_VERSION}-rc${RELEASE_RC_NO}`, e.g. `v1.3.0-incubating-rc0`
 
+> NOTE: After all the voting passed, be sure to create a final tag with the pattern: `v${RELEASE_VERSION}`
+
 4. Package the release binaries & sources, and upload them to the Apache staging SVN repo. Publish jars to the Apache
 staging Maven repo.
 
@@ -193,6 +195,14 @@ build/release/release.sh publish
 
 To make your release available in the staging repository, you must close the staging repo in the [Apache Nexus](https://repository.apache.org/#stagingRepositories). Until you close, you can re-run deploying to staging multiple times. But once closed, it will create a new staging repo. So ensure you close this, so that the next RC (if need be) is on a new repo. Once everything is good, close the staging repository on Apache Nexus.
 
+5. Generate a pre-release note from GitHub for the subsequent voting.
+
+Goto the [release page](https://github.com/apache/incubator-kyuubi/releases) and click the "Draft a new release" button, then it would jump to a new page to prepare the release.
+
+Filling in all the necessary information required by the form. And in the bottom of the form, choose the "This is a pre-release" checkbox. Finally, click the "Publish release" button to finish the step.
+
+> Note: the pre-release note is used for voting purposes. It would be marked with a **Pre-release** tag. After all the voting works(dev and general) are finished, do not forget to inverse the "This is a pre-release" checkbox. The pre-release version comes from vx.y.z-incubating-rcN tags, and the final version should come from vx.y.z-incubating tags.
+
 ## Vote on the release candidate
 
 The release voting takes place on the Apache Kyuubi (Incubating) developers list (the (P)PMC is voting).