Update access list in COMMUNITY.md

[kingdonb]

I realize that the document reads:

Access to things
In case you need access to a particular Flux resource to fulfil your role as team member, please file an issue on this repository and tag some of the folks in the previous section.

Below we list resources that are not tied to GitHub permissions. You can assume that the core Flux maintainers have access, maintainers of the community repository and sometimes CNCF staff as backup.

For people listed below we made exceptions:

and so, that I am a maintainer on the COMMUNITY team means I should probably not put my name in this list, however. There are some things in this list that I do not have access to (namely Twitter, LinkedIn) even now, as a maintainer ...

I got halfway into crafting this PR before I understood that from reading the COMMUNITY.md document a couple of times. Still I wonder if we shouldn't revisit this list and make sure that all access listings are correct and current! While I'm here...

Are there any core maintainers who need access to any more of these socials than they currently do have? Let's have a check-in here on the issue, for anyone who is interested—is there at least someone active on the maintainers team with current manager-level access to each of these?

• FluxCD LinkedIn Group
• FluxCD Twitter Handle
• FluxCD YouTube Channel

(This may also serve as a call for volunteers!)

[kingdonb]

I confirmed that we've all got the access we need on the internal #flux-maintainers channel