Chore: Add the guide for the plugin developer

[barnettZQG]

Description of your changes

Fixes #

I have:

• Read and followed KubeVela's contribution process.
• Related Docs updated properly. In a new feature or configuration option, an update to the documentation is necessary.
• Run yarn lint to ensure the frontend changes are ready for review.
• Run make reviewableto ensure the server changes are ready for review.
• Added backport release-x.y labels to auto-backport this PR if necessary.

Special notes for your reviewer

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: -0.07 ⚠️

Comparison is base (47f2313) 61.16% compared to head (0f329b5) 61.09%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #780      +/-   ##
==========================================
- Coverage   61.16%   61.09%   -0.07%     
==========================================
  Files         109      109              
  Lines       19108    19108              
==========================================
- Hits        11687    11674      -13     
- Misses       5975     5986      +11     
- Partials     1446     1448       +2     

Flag	Coverage Δ
apiserver-unittests	33.77% <ø> (+<0.01%)	⬆️
server-e2e-tests	49.70% <ø> (-0.11%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

see 5 files with indirect coverage changes

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.