Document adopters

[cassidyjames]

Possibly just in the README? Any org that is publicly using Osprey should be added for visibility.

[lasomethingsomething]

Or you might consider an ADOPTERS.md, like: https://github.com/vmware-tanzu/velero/blob/main/ADOPTERS.md

[cassidyjames]

@lasomethingsomething oh, that's a convention I hadn't seen! I like the README for visibility, but the dedicated file is probably nice once it gets to a certain size. 🤔