Docs: clarify "plumbing" v.s. "porcelain" in git(1) usage
Our use of plumbing v.s. porcelain doesn't reflect the reality or desired usage. See the 2nd commit message for an elaboration on that.
Our use of plumbing v.s. porcelain doesn't reflect the reality or desired usage. See the 2nd commit message for an elaboration on that.