Add autoID for definition terms

[bep]

Fixes #13403

[jmooring]

I'll take this for a spin in a bit.

[jmooring]

Something to think about for the docs site... since we don't have a dt render hook, should we use something like https://github.com/bryanbraun/anchorjs to render anchors for both headings and dt elements?

[bep]

should we use something like https://github.com/bryanbraun/anchorjs to render anchors for both headings and dt elements?

No. If we want to do this via JS it can be easily be done in "five lines" in a AlpineJS controller.

[jmooring]

This is very slick. Works great with the link render hook on the docs site (e.g., validate id existence and check for duplicates).

And thanks for this too:

A [link](/a/b) in the heading --> id becomes "a-link-in-the-heading"
: something

[jmooring]

If we want to do this via JS

I have no preference how we do it... this is the last task in eliminating the h6 hack.

[bep]

I have no preference how we do it... this is the last task in eliminating the h6 hack.

I added a fix for this in gohugoio/hugoDocs#2914

I like definition lists for documentation and making them as easy to use as possible (by making them easy to link to) is worth it, I guess, so I suggest we go with the approach above. It's simple enough.