[Enhancement] Expose internal functions for shorthands

[vitto4]

Before submitting

• I am using the latest version of Quarkdown.
• I have checked the wiki to confirm this feature doesn't already exist.
• I have searched existing issues for duplicates.

Description

Shorthands like <<<, ## Heading, ![](image) or [text](link) could also be exposed¹ as quarkdown .functions, so that they may be used in scripts ; just like can also be written .br.

I hope I didn't miss anything, but afaik there is no way to do something like this at the moment :

.foreach {1..4}
    n:
    .heading {Heading of level .n} level:{.n}

Proposed syntax or behavior

Additional context

No response

Footnotes

1. See also how Typst does it. ↩

[iamgio]

Good one!

[iamgio]

#384 and #386 bring .heading and .pagebreak primitive wrappers. More are coming soon