Update `docs/admin.md` (#46060)
Update `docs/admin.md` (#46060)

Describe the blessing thing, and a few updates (mainly the pointer to
the new project board).
georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped,mcliment/DefinitelyTyped,georgemarshall/DefinitelyTyped,markogresak/DefinitelyTyped,georgemarshall/DefinitelyTyped