Use META_UNDERLINE_ON_HOVER in built-in class reference

[Mickeon]

Supersedes #64861

I am moved. Thank you #89024.

You can see that those constants are harder to notice but it's nothing that can't be adjusted...

Please feel free to share opinions but this is the way to go now. It's consistent with the online docs, and it's just... almost objectively good, compared to #64861 ?

Note that this PR does not affect [url] tags at all for clarity.

[dalexeev]

The effect looks nice to me. The link is already highlighted, but you can hover over it to make sure the text is clickable. We could add an editor setting meta_underline_behavior (always, on hover, never) but let's wait until someone actually requests it.

You can see that those constants are harder to notice but it's nothing that can't be adjusted...

I agree. Could you do it please?

[Mickeon]

I'm questioning how because I wouldn't want them to be the accent color as it has helped distinguish them from properties/methods more. I could also just make an underline exception for constants and flags? That sounds fine to me for now.

Last time I completely retouched the way built-in docs are stylized I explored the idea of hue-shifting the accent color for different "things". I really liked it back then and I could experiment on it furthermore after this PR.

[Mickeon]

Updated the PR to make an exception for constants and enums for now. Improvements in styling will come in bulk at a later time and I'm looking forward to try them

[Chubercik]

holy compression on these GIFs 😳

other than that looks good to me :)

[Mickeon]

Alright have a small video then!
https://github.com/godotengine/godot/assets/66727710/f83b0eff-cc8c-4aa0-8495-37968293fdfc

[Mickeon]

Rebased after the recent fun stuff. Would be nice to see this along with the other fruits of our labour.

[akien-mga]

Thanks!