Add anchors for headings in post content

[rmccue]

So that you can deep-link into a post, adding anchors to headings in the same way that GitHub has them would be groovy.

h/t @tareiking

[thewebprincess]

Maybe related. I made a post in the block editor and added in skip links https://updates.hmn.md/2020/07/29/leveraging-the-power-of-slack-workflows/ but was a bit irked to find that the skip links don't work. When I wrote the post the href=“#standupnotesworkflow” is automatically being converted to “about:blank#standupnotesworkflow” which suggests the problem, but even if I replace that with the full URL it still doesn’t work :poopcry:

Is this an H2 thing? Can we fix it for long form posts? @rmccue (thanks for the prompt to add to github @kadamwhite )

[rmccue]

Looks like this is a slightly separate problem @thewebprincess, it's actually the over-eager sanitisation stripping out the IDs and absolutising the URLs. Should be easier to fix than this main issue. Edit: IDs are fine, it's just a quirk of how the parser works that the anchors are broken in the links. PR incoming.

[CoreyBenefiel]

I'm a big fan of this one. It's something we would like to do in the Playbook as well given the benefits.

[CoreyBenefiel]

@kadamwhite as discussed, I'd like to expand on this ticket to use those anchors to enable a page menu, similar to a Playbook page menu. The Playbook redesign will turn the current content menu (running across the top of the page) into a sidebar widget. Perhaps we could do something similar here?

[CoreyBenefiel]

Addressed by #531