Inserter: Show heading level shortcuts in the slash command

[melchoyce]

What problem does this address?

When laying out a page, I often want to work on the overall hierarchy and structure first, which often means adding a bunch of headings at once. You can use the slash command to insert things like /h3 or /h4 directly, but it isn't exposed in the slash autocomplete — you need to know it exists.

What is your proposed solution?

When you type /h3 or /h4, etc, we should show an autocomplete for "heading 3," etc. in the slash command list.

[ntsekouras]

Actually there is support, by typing the alike /h3 and pressing Enter, implemented here: #26597. It's similar to the ### handling for heading insertion, it works for now, but could be improved by giving some UI indication for such transformations.

[melchoyce]

Oh! Never mind then 😂 I assumed because there wasn't an autocomplete popping up, it wouldn't work. Should I close out this issue, or update it to be about the UI?

[ntsekouras]

I think it can be updated 😄

[mtias]

It might make sense to treat each heading level as a variation.

[mayankguptadotcom]

Oh! This will be so useful!
I understand that Gutenberg supports markdown - but still this can be super helpful for those who don't want to learn markdown.

[spencerfinnell]

It might make sense to treat each heading level as a variation.

@mtias even if they aren't "real" variations, I think mimicking the behavior of variations makes sense in this instance: #53963 (comment)