Hard to figure out where each feature setting is located

Problem

Originally raised at #199370 (comment 322866539) by @mlanders.

When you want to change a feature setting on a project, you visit Project > Settings. And once you hover your mouse on Settings, you see multiple category pages that

• "General"
• "Member"
• "Integrations"
• "Webhook"
• "Repository"
• "CI/CD"
• "Operations"
• "Pages"
• "Audit Events"

Now, let me ask you a question. Which category page will you visit when you want to change the following feature setting?

• Merge request approvals
• Feature Flag
• Merge Train
• Protected Environments
• Service Desk
• Deploy Tokens

TBH, it's hard to guess. For example, when you configure merge request approvals rules, you don't find "Merge Request" category in the Settings. So you'd guess what's close to the context at next, maybe... "General" or "Member"? Who knows. (The answer is Settings > General > "Merge request approvals" in this case)

This is a quite counter-intuitive that users have to dig around Settings > [Category] page until they find a desired one (there is even a possibility that GitLab doesn't support the desired setting yet). I think one biggest problem is that each feature page Project > [Category] and feature setting page Project > Settings > [Category] is out of sync (e.g. We have Project > Merge Requests as feature, but we don't have Project > Settings > Merge Requests as feature setting), so it makes it even harder to guess where the desired config option is located.

Proposal

TBD