reorder list of orgs based on gsoc participation and alphabetically

[mirca]

addresses #252 cc @bsipocz

[bsipocz]

approving for the sake of merge-ability

[bsipocz]

timelab and juliaastro is also part of gsoc, but glue is not really (or it's borderline, I take the sunglue project a sunpy one rather than a glue one).

But it either case, let's see what others think about, my original idea may be bad to begin with :)

[mirca]

But it either case, let's see what others think about, my original idea may be bad to begin with :)

sure :) I've moved juliaastro and timelab to the first pack just in case.

[bsipocz]

OK, I say we go with it. If anyone else have opinions strong enough to open a PR, please do a follow-up one.

[bsipocz]

(I've also added a commit with the new matrix link for astronomy-commons, that case it doesn't need another round to get it merged).