Add bundle prefixes to rails/rake/rubocop commands

[jaydorsey]

Description of changes

We're isolated in the docker containers so we shouldn't run into conflicts here, but this closely reflects the commands as you'd want to run them locally, if you weren't using a Makefile. So, I'd consider it more a "documentation" fix than anything

Also cleaned up some trailing empty spaces on commands.

This might be considered a style/preference but I consider it more of a good rule to follow when using bundler. Please feel free to close it if it doesn't add any value.

Issue Resolved

No issues closed. This is a general documentation/cleanup suggestion

[jaydorsey]

As an FYI, I actually just ran into this issue on a separate PR that I'm working on, so I guess it's not quite as much of "just" a style issue, or isolated because it's in docker, as I thought