Auto merge of #6749 - calebcartwright:docs-publish-command, r=ehuss
Minor doc fix for publish command synopsis
I think the synopsis for the [publish command doc]( https://doc.rust-lang.org/stable/cargo/commands/cargo-publish.html) should be `cargo publish` but it currently has `package` (screenshot below).
Took a shot at making the change, not positive I did it the correct way though 😄
