add github-actions documentation

[Killpit]

There was an issue about documentations in GitHub Actions and had to look for the GitHub repo, added GitHub Actions documentation in ci-cd part to make sure it can easily be learned and utilised for CI/CD without further research for users

[sigmavirus24]

I think you also need to add this elsewhere for it to be included in a table of contents and be built and indexed properly

[Killpit]

@sigmavirus24, I did the recommended changes, can you check it again?

[Killpit]

@sigmavirus24 I did the changes, can you check again

[sigmavirus24]

I left specific comments but please look at the other rst files to understand the proper way to write RST and follow the same general style

[Killpit]

@sigmavirus24 can you check the changes again, I looked at your suggestions and other .rst files to format the changes and also formatted the list table to further be compliant with the .rst rules.