feat: show docs with icons in sidebar

[thomasheartman]

Adds icons to sidebar documentation and removes the link when you can't interact with it.

I'm a little concerned that this won't be very accessible at the moment, because we don't announce that anything has changed (i.e. there's no way to find out that the text has changed if you can't see it), and the text isn't labeled as describing anything. (this is being addressed in #7110 )

There's a few caveats to this:

1. we don't set a min height at the moment. I've avoided this because we use the sidebar a number of other places and I wanted to touch as little as possible. This means we can still get height adjustments
2. The new project icon doesn't have the same proportions as the mui icons. This adds some additional jank. We should probably look at this, though.

[vercel]

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Name	Status	Preview	Comments	Updated (UTC)
unleash-monorepo-frontend	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	May 22, 2024 11:36am

1 Ignored Deployment

Name	Status	Preview	Comments	Updated (UTC)
unleash-docs	⬜️ Ignored (Inspect)	Visit Preview		May 22, 2024 11:36am

[thomasheartman]

It's still there, I've just removed the stroke and fill, so that we can set it per instance.