Workaround for the info on fenced code blocks being hidden behind the jump: Go to https://askubuntu.com/editing-help#code (linking directly to section in question). All section links in that page expand the relevant section if possible.
Nmath, your suggestion is nice. But I am not sure if the moderators can edit the content in https://askubuntu.com/editing-help and https://askubuntu.com/help/formatting.
I have another suggestion. We can post an FAQ post about formatting in Ask Ubuntu Meta. Something similar to this: How do I format my code blocks?