Automate release process

[pkosiec]

Is your feature request related to a problem? Please describe.

Currently, the release process for BotKube consists of a set of manual steps (as described in https://github.com/infracloudio/botkube-docs/pull/74). Fortunately, most of the actions are automated in a form of Bash scripts.

We can improve this by automating all the steps, including:

• pushing Helm release charts
• publishing changelog as a part of GitHub release
• triggering rebuilding botkube.io docs

from a single entry point, which could be a GitHub Actions pipeline.

Also, create release branches (release-x.y) for any major and minor releases.

Describe the solution you'd like

A GitHub Actions pipeline, which does all the steps described in the instruction automatically. It could be run manually:

AC

• Implement the GH Actions workflow on botkube repo:
  • get rid of the .release file
  • create release branch (unless it's a patch release) and checkout it
  • push images
  • publish Helm release charts
  • create draft GH release
    • Publish changelog there (we can use different tool if that make it easier - e.g. gren)
    • We can get rid of CHANGELOG.md
  • we can use Bash scripts
  • support both major/minor and patch releases - test both scenarios on your fork
• Implement GH Actions workflow on docs repo:
  • create a new docs version
  • You can base on https://github.com/capactio/website/blob/main/.github/workflows/make-release.yaml
• Update release documentation
• WARNING: Analytics key must be included in the built binary
  • test that as a part of the release candidates and official release

Examples

• https://github.com/capactio/capact/blob/main/.github/workflows/make-release.yaml (probably won't be that useful)
• https://github.com/capactio/website/blob/main/.github/workflows/make-release.yaml (Docusaurus website)