Add SonarCloud documentation

[haani-niyaz]

SonarCloud CI usage docs must be added to https://github.com/rog-golang-buddies/golang-template-repository/blob/main/docs/continuous-integration/sonarqube.md.

The filename must also be updated from sonarqube.md to sonarcloud.md.

Could I take this one?

[haani-niyaz]

Please do! If it is not assigned to anyone, it is open season 😄 .

[haani-niyaz]

SonarCloud has been descoped for now since we require a multi tenanted approach to create a project for each repo. The descoped implementation reused the same project for all repos.