Add slug and tags to config.json

[0x647262]

Closes #137
Closes #118
Closes #117

Filled the tags out to the best of my ability. If I'm missing anything, let me know and I'll get it added!

[ErikSchierboom]

I think this is the language's official introduction text verbatim, right? We usually don't want to copy things literally due to licensing issues. In https://github.com/exercism/d/pull/144/files, I took a stab at writing a blurb. How does that look like? Maybe you can use that and tweak it a bit?

[0x647262]

I opted to leave your blurb as-is. I think it fits the language just fine!

[ErikSchierboom]

Thanks for working on this BTW!

[0x647262]

@ErikSchierboom I'd like to tackle #117 with this merge as well, if possible.

I took a look at the key features documentation on: https://github.com/exercism/docs/blob/main/building/tracks/config-json.md#key-features, but it seems there are no predefined features there. Would grabbing shared key features from other tracks config.json files be fine in this case?

[ErikSchierboom]

I'd like to tackle #117 with this merge as well, if possible.

We usually prefer to merge things sooner than later, but I can keep this open if you'd like :)

[...] it seems there are no predefined features there.

That's correct. This is due to the key features being track-specific highlights.

Would grabbing shared key features from other tracks config.json files be fine in this case?

The idea is that these key features showcase why a student would want to join that track. So usually you'd come up with the six things that showcase the track best, and then write the text for them. There is likely some overlap, so you could definitely take inspiration from other tracks, although it is likely that the text needs to be modified.

[0x647262]

@ErikSchierboom all set!

[ErikSchierboom]

LGTM! Thanks

[ErikSchierboom]

@0x647262 You can see the key features on https://exercism.lol/tracks/d (provided you've not joined the track)