VS Code WSL Install Rework

[jamesjuett]

This PR does a few things:

• Removes some duplication in the prerequisites and install sections.
• Updates installation instructions to remove unnecessary computer reboot. Instead, add a note to code . pro-tip that restarting the shell may be required. (https://github.com/microsoft/vscode/issues/74116)
• Changes extension install to use VS Code UI
• Adds some context on WSL mode
• Fixes #155
• Partial work towards #149

[github-actions[bot]]

The spec from this PR is available at https://preview.sesh.rs/previews/eecs280staff/tutorials/156/.

^{(Available until Sun Oct 08 2023.)}

[jamesjuett]

LGTM. I pushed a change to the WSL Mode pitfall callout. Take a look at f674306

Thanks! Splitting it up is a good idea.

[jamesjuett]

Chatted with @amirkamil about this today. He's going to review and run through the new instructions before we merge.