Ruby

Fleshed out Ruby conventions further, with sections on Rails and Bundler. [fixes #2]
Ah, that's helpful to understand.

I'm a bit scared of `bundle update` updating to new major versions, especially for newer engineers who might expect it to be safe. I like knowing that `bundle update` can be run and (mostly) not break anything.

That said, are you cool with the conventions written here?

> Either way, I'm not necessarily promoting this approach as much as pointing out that I have been thoughtful in adopting it.

Totally. Sorry if it sounded like I was implying the opposite.