Using Git in the Real World: Add assignment section

[SumonGFC]

Because

Maintainers are trying to add an assignment section to all lessons. Lesson "Using Git in the Real World" does not currently have an assignment section, which this PR will add.

This PR

• Rename header on line 20
• wrap relevant sections in lesson-content__panel div

Issue

Closes #27255

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