A Deeper Look at Git: Restructure code block

[carisaelam]

Because

I updated the lesson file for "A Deeper Look at Git" to improve readability and accuracy by removing non-bash syntax from the bash code block. This change also corrected the syntax highlighting issues, ensuring the code will display correctly.

This PR

• Removed text ("You can amend the commit now, with" and "Once you're satisfied with your changes, run") from code block
• Replaced with ("The command above will allow you to amend the commit. Once you're satisfied with your changes, you can complete the rebase with the following:") outside of the code block as specified in acceptance criteria

Issue

Closes #28298

Additional Information

Pull Request Requirements

• [x] I have thoroughly read and understand The Odin Project curriculum contributing guide
• [x] 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
• [x] The Because section summarizes the reason for this PR
• [x] The This PR section has a bullet point list describing the changes in this PR
• [x] If this PR addresses an open issue, it is linked in the Issue section
• [x] If any lesson files are included in this PR, they have been previewed with the Markdown preview tool to ensure it is formatted correctly
• [x] If any lesson files are included in this PR, they follow the Layout Style Guide