Teams without members

[skade]

For the lack of better modelling, there's currently some teams with just one members. For example, in the compiler team: Compiler Performance, LLVM, MIR Optimizations, Traits.

https://www.rust-lang.org/governance/teams/compiler

These have fluctuating membership, but (optionally?) a contact point and a repository attached.

It's useful to model them differently, to also display them differently (maybe more condensed) on the website. "Responsibilities" or "Subjects" sounds like a good first iteration, but I'm sure there's something better.

Relevant website issue: rust-lang/www.rust-lang.org#670