Add links to "features" page, and mark default features

[Swatinem]

This adds links to all the features, dependencies, and dependency features for easy navigation.

It also marks all the transitive features with a (default) marker.

I changed that so the secondary sort order is alphabetic, as that might make more sense than sorting by number of sub-features.

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Fixes #2530 and #2531

This was just a quick and dirty hack during RustFest impl Days, and we were discussing some more ideas related to the Features page in general.

The Features page now looks like this, with all the links being clickable:

[GuillaumeGomez]

Unless you know what the * is about, it's not useful. Why not instead add [FEATURE] (default)?

[syphar]

some first comments from the first test:

• deffault (default) is perhaps a little much :)
• I'm not sure if all the default markers are correct. Example: sentry-tower subfeature in sentry feateure

generally especially the top section with all default features is a little noisy, I'm not sure how this could be improved, and would merge as-is when not buggy.

[GuillaumeGomez]

We still need a visual marker to make it obvious that it's not part of the feature name, hence why I suggested parens. Without parens, we then need some styling.

[syphar]

@GuillaumeGomez currently it looks roughly like this:

do you mean something else?

[GuillaumeGomez]

The (default) sounds good to me. But I think I misunderstood what you meant in:

• deffault (default) is perhaps a little much :)

[Swatinem]

I marked this as draft as I will iterate on this a bit more.
In particular, I believe it makes sense to also tackle #2530 at the same time, as parsing the opaque subfeature into a typed enum would make a ton of sense here as well.

[syphar]

In particular, I believe it makes sense to also tackle #2530 at the same time, as parsing the opaque subfeature into a typed enum would make a ton of sense here as well.

this would be super awesome!

[Swatinem]

It took a while until I got some more time to work on this.

Now this should be fairly complete with interlinks to all the own features, dependencies and features of dependencies. See the screenshot in the updated PR description.

[syphar]

short update @Swatinem :

I'm sorry looking at this PR takes so long, we were finishing a bigger refactor (#2292), which will also mean that we will have to update this PR after it's merged.

Will look at the PR anyways right now

[syphar]

first manual test: this is beautiful :)

[syphar]

@Swatinem #2292 is merge now, you need to resolve some conflicts.

Will try to look into the review tomorrow or today in the evening

[syphar]

this is really awesome :)

( I'll be offline / on a trip for next week, I'll deploy this the week after )

[GuillaumeGomez]

Suggested change

	{%- let is_default = self.is_default_feature(name) -%}
	{%- let is_default = is_default_feature(name) -%}

(just nitpicking ^^)

[GuillaumeGomez]

Same, no need for self..

[GuillaumeGomez]

Same here too.

[GuillaumeGomez]

Gonna send a little cleanup, but it's really nitpicking. I also saw some data-id and I wonder if we use them for tests or not...