Porting from only/except to rules
### Problem to solve
The `only` and `except` CI job keywords are being deprecated. However, many of the `only` special keys don't seem to have analogues in the `rules` structure. How can I do `only: [branches@group/repo]` now? `triggers`? `schedules`?
### Proposal
For each old keyword, give an example of the new syntax.
### Who can address the issue
Anyone with the requisite CI configuration knowledge.
issue