[doc] Improve documentation about the available renderers (PMD/CPD)

[adangel]

PR Description:

• CPD has an own subsection now
• Extra page for CPD's renderers
• Extra page for PMD's renderers including examples

Note: while the CPD page is moved in the sidebar, the permalink stays the same.

[pmd-test]

	1 Message
📖	This changeset introduces 0 new violations, 0 new errors and 0 new configuration errors, removes 0 violations, 0 errors and 0 configuration errors. Full report
✅	This changeset introduces 0 new violations, 0 new errors and 0 new configuration errors, removes 0 violations, 0 errors and 0 configuration errors. Full report

Generated by 🚫 Danger

[oowekyala]

Thanks! I'll merge this before #2414 and #2404 so that those can update the new page too

Also, there wasn't an issue ticket to begin with, but maybe we can add PRs like this directly to the list of "fixed issues" in the release notes. It describes and fixes an issue at the same time

[adangel]

Also, there wasn't an issue ticket to begin with, but maybe we can add PRs like this directly to the list of "fixed issues" in the release notes. It describes and fixes an issue at the same time

Sounds good. I sometimes did this before as well. The only thing I'm unsure about is: when to add an entry to the release notes? If it's an issue, that is fixed - always - that's easy to decide. Simple rule. But for pull requests, there is no such simple rule... but we can try to do this in the future. For external PRs we might need to mention it twice in the release notes (under fixed issues and under external contributions).