Ruby: Linting and RuboCop: Fix code blocks

[scheals]

Because

There were additional back quotes and some blocks were described as bash instead of ruby or yaml

This PR

• Removes unnecessary back quotes.
• Correctly describes code blocks.

Issue

nil

Additional Information

Pull Request Requirements

• I have thoroughly read and understand The Odin Project curriculum contributing guide
• The title of this PR follows the location of change: brief description of change format, e.g. Intro to HTML and CSS lesson: Fix link text
• The Because section summarizes the reason for this PR
• The This PR section has a bullet point list describing the changes in this PR
• If this PR addresses an open issue, it is linked in the Issue section
• If any lesson files are included in this PR, they have been previewed with the Markdown preview tool to ensure it is formatted correctly
• If any lesson files are included in this PR, they follow the Layout Style Guide

[JoshDevHub]

Thanks for fixing these!