Add VS Code Productivity Shortcuts page

[JadeCheah]

Fixes #184

This PR adds a new “VS Code – Productivity Shortcuts” page to help students improve their coding efficiency.

• introduces commonly used productivity features in VS Code, such as:
  • Command Palette for quick access to all commands.
  • Multi-cursor editing, integrated terminal, and other editing/refactoring shortcuts.

[jasmiinee]

Hey, I like how comprehensive and well structured this guide is! But I do have some minor suggestions.

Code Formatting

In the Command Palette section, you mention "You can use it to run tasks, format code, open settings, manage extensions, and more." However, there's no details provided on how to actually format code. I think it would be helpful to add a dedicated section for this.

• Format Current Selection: {{icon_windows}}/{{icon_linux}} Ctrl+K Ctrl+F | {{icon_apple}} Cmd+K Cmd+F
• Format Entire Document: {{icon_windows}}/{{icon_linux}} Shift+Alt+F | {{icon_apple}} Shift+Option+F

Comment and Uncomment Lines

I think it would be useful to add a section on toggling comments since it's handy for debugging or testing different code paths quickly.

• Toggle Line Comment: {{icon_windows}}/{{icon_linux}} Ctrl+/ | {{icon_apple}} Cmd+/
• Toggle Block Comment: {{icon_windows}}/{{icon_linux}} Shift+Alt+A | {{icon_apple}} Shift+Option+A

Go to Definition

I think this would also be a great addition. When navigating larger codebases, being able to jump to where a symbol is defined saves a lot of time.

• Go to Definition: F12 | {{icon_windows}}/{{icon_linux}} Ctrl+Click | {{icon_apple}} Cmd+Click