README files for Helm charts are generated using helm-docs.

Each chart should contain a README.md.gotmpl file that describes how the README.md of the chart should be generated.

Normally, this file can be the same as the primary template in [docs/templates/README.md.gotmpl] or a symlink pointing to it:

cd charts/CHART
ls -s ../docs/templates/README.md.gotmpl

Copy the file to the chart directory if you want to customize the template. Note: Don't forget to add README.md.gotmpl to .helmignore. Then run make docs in the repository root.