docs(cli): correct headings in argo command's Long description

[agilgur5]

Motivation

• these were H1s before, and there can only be 1 H1 per page
  • they also should be H4s, because these are under the "Synopsis", which is an H3
    • this fixes some very wacky formatting in the docs as well as HTML semantic errors

Modifications

• h1 -> h4 in argo root command's Long description

Verification

Before:

After:

[terrytangyuan]

This should be docs instead of fix?

[agilgur5]

It is a CLI change, though in this case it impacts the generated docs more than the CLI help text itself. I labeled the PR as both

Speaking of generated docs, I realized I forgot codegen here. I felt like something was missing or I ran the wrong command. Sick 😷 brain misses some details 😅, this is why I'm holding off on doing some complex code reviews right now

[terrytangyuan]

Generated docs are docs change.

[agilgur5]

Sure, but it also changes the source code / metadata of the CLI. nbd either way to be fair, but we're not currently cherry-picking docs PRs, which we will need to do for versioned docs. so we'll need some way to decipher docs PRs that are for new features vs docs PRs for existing features (most will fall into the latter, I imagine). semantically, it's generally quick to tell from a given PR, but there's no way to do that automatically right now unless we differentiate in some way

[agilgur5]

fixed codegen

[agilgur5]

Merged master to get new status checks / actions from #12006 to run