Sticky issue description feature request

not sure I'm posting this in the right place.

Sometimes when working on an issue with a lot of comments in it, I need to refer quite a lot to information (IDs, etc) written in the issue description. This involves a lot of scrolling.

It would be cool if the issue description block could stick to the top of the issue wrapper as the page is scrolled. Collapse it if it's large, but allow to be expanded at the click of a button.

This would make it much easier to keep important data visible on-screen as we work.