Rough draft of the Committing guidelines

This is the rough draft and will have many more changes as we flesh out exactly what we want our committing standards to be.
Note: the Robottelo Standards link will be broken until we create that document.
Please drop the blank lines from this code block. Real shell scripts should not have a blank line between every single statement, and I'd like it if this code block is at least somewhat representative of a shell script. (The `$` are fine for obvious reasons, and I'm not going to insist on a shebang. "somewhat" is the key qualifier here.)