release progress guide

[pacoxu]

RELEASE.md

• main branch and release branch defination
• release process, including release note, release blog, release CI(blocking CI)
• patch process: cherry-pick requirements and scope(CVE and critical issues by default)
• general release plan, such as a release per year or every 3 months

[pacoxu]

See https://github.com/HuaweiCloudDeveloper/cluster-api-provider-huawei/blob/master-dev/RELEASES.md.