Proper release process

[bo0tzz]

Currently the chart is built and released whenever a new chartVersion is pushed to main. Depending on the options out there, it would be nice to make this a bit more deliberate to increase the control over when new versions are published.

Currently releases do not include any changelogs. This should be fixed so that both the github releases and the artifacthub page properly display a changelog, and ideally so that these changelogs also show up in PRs generated by tools like Renovate.

[hiteshnayak305]

i will try change log generators for CHANGELOG.md and artifacthub annotations. for now we need to update contribution guide to use conventional commit messages.