Addon Zookeeper-operator

[MdSahil-oss]

Description of your changes

Addon Zookeeper-operator

How has this code been tested?

Checklist

I have:

• Title of the PR starts with type (e.g. [Addon] , [example] or [Doc]).
• Updated/Added any relevant documentation and examples.
• New addon should be put in experimental.
• Update addon should modify the version in metadata.yaml to generate a new version.

Verified Addon promotion rules

If this pr wants to promote an experimental addon to verified, you must check whether meet these conditions too:

• This addon must be tested by addon's e2e-test to guarantee this addon can be enabled successfully.
• This addon must have some basic but necessary information.
  • An accessible icon url and source url defined in addon's metadata.yaml.
  • A detail introduction include a basic example about how to use and what's the benefit of this addon in README.md.
  • Also provide an introduction in KubeVela documentation.
  • It's more likely to be accepted if useful examples provided in example dir.

[MdSahil-oss]

@wonderflow @wangyikewxgm According to me this addon is done and works fine. Please review it and let me know if I have to change something.

[wangyikewxgm]

Good job. LGTM