Create roadmap using project boards

[JamieDanielson]

If SIGs have a clear priority queue using a project board, new contributors and end users will see where the issues they are interested in fit. This can be used to encourage contributors to work on other higher priority issues to help unblock their own.

[codefromthecrypt]

if such a thing became common, would be easy to find if added to this table https://github.com/open-telemetry/community?tab=readme-ov-file#specification-sigs

[mx-psi]

On the Collector specifically we would likely have multiple boards; for example we currently have the "Collector v1" project board Collector: v1 which is a subset of all the work being done in the Collector. I think we should encourage the usage of projects (or, more generally, of transparency with respect to roadmap and current work) while being mindful that every SIG will handle this differently

[svrnm]

I think many SIGs might not be aware that (a) boards are available, (b) they can use them and (c) they are good, since in the past github boards just sucked, the new ones are good.

To address low hanging fruits first and have a quick win, we could check which SIGs do not yet have a board and get in touch with them asking if they want to have one and if they need assistance setting one up?