Add nodejs/gyp team

It would be good to have a GYP team to cc/ in issues.

I know @refack and @bnoordhuis have done a fair amount of work on GYP in the past, not sure who else has experience there, maybe @seishun ?

If you want to be on the team, reply here and I'll add you 😁 .

I also formatted the table while I was there. Happy to change it back if people prefer unevenness to long lines.

Checklist

• documentation is changed or added
• commit message follows commit guidelines

Affected core subsystem(s)

doc, build