[Improvement] I cannot find feature list of KubeBlocks MySQL / PostgreSQL / etc.

[realzyy]

Is your improvement request related to a problem? Please describe.
I don't know whether using KubeBlocks MySQL in production is suitable.

If this is a new function, please describe the motivation and goals.
no, it's a requirement for documentation.

Describe the solution you'd like
I would like to see the status of the engines and versions (test only or production ready).
It's better to learn features supported for different engines.

Describe alternatives you've considered
Additional context