add missing controller.config.annotation docs

[coolbry95]

Proposed changes

This is in the helm chart readme but not in the docs.

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

[codecov-commenter]

Codecov Report

Merging #3285 (b20bd63) into main (71745fb) will decrease coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #3285      +/-   ##
==========================================
- Coverage   52.67%   52.64%   -0.03%     
==========================================
  Files          59       59              
  Lines       16107    16107              
==========================================
- Hits         8484     8480       -4     
- Misses       7341     7343       +2     
- Partials      282      284       +2     

Impacted Files	Coverage Δ
internal/k8s/configuration.go	95.39% <0.00%> (-0.37%)	⬇️

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[lucacome]

Thanks @coolbry95. FYI this doc is hopefully going away soon and replaced with a link to deployments/helm-chart/README.md so we have a single source of truth