Add @rchincha as dist-spec maintainer

[caniszczyk]

https://github.com/opencontainers/tob/issues/95#issuecomment-818968500

We will have the existing maintainers vote via this PR with a LGTM / +1

• [ ] Derek McGowan (@dmcgowan)
• [ ] Jimmy Zelinskie (@jzelinskie)
• [ ] Josh Dolitsky (@jdolitsky)
• [ ] Mike Brown (@mikebrow)
• [ ] Stephen Day (@stevvooe)
• [ ] Vincent Batts (@vbatts)

Signed-off-by: Chris Aniszczyk caniszczyk@gmail.com

[vbatts]

closing for now