Clean-up collaborations page

[bbockelm]

The collaborations page (https://iris-hep.org/collaborations) looks a bit basic. At the minimum, each project should have a sentence or so on how they intersect with IRIS-HEP (not just NSF project numbers!).

Additionally, (at least) the following are missing:

• SLATE
• SOTERIA
• New Awkward Array CSSI
• EWMS
• New DarkMatter / ServiceX CSSI
• Any other HEP collaborations working with IRIS.