Try to avoid confusion in how-to-build-and-run.md

[sslime336]

This pr is the follower of #1710, which didn't finish it's job perfectly.

[jyn514]

@sslime336 this needs to be rebased over master - see https://rustc-dev-guide.rust-lang.org/git.html#advanced-rebasing for instructions. You'll want to drop all except the last commit ("Try to avoid confusion").

[sslime336]

yes, I'm sorry I did not handle this well. I will handle this sooner.

[sslime336]

@jyn514 Okey, here's new pr #1713 (hope this time it could be allright :P )
Sorry for making the workflow so messy.

[jyn514]

that's ok! thank you for fixing it :)