Add @jamiebuilds and @devongovett as observers

[jamiebuilds]

We've been working on the Parcel bundler and writing our own specifications around module resolution. We met with @guybedford today to talk about how some of our work aligns with the work of the node modules committee and work from other bundlers, and he suggested that we attend the next modules meeting.

[guybedford]

I've created a PR in #364. Even if we don't get that merged soon you can follow the instructions to join the meeting tomorrow at #362.