[Getting Started] Add more content for experienced users

[digitarald]

Getting Started so far has two sections focused on beginner user: setup and fundamentals.

A new intermediate section should include the prior ideas from the welcome page and other content for power users (work in progress):

• Interactive Playground
• Quick Open (could also be in Fundamentals)
• Split Screen
• Clone from GitHub
• Shell Command (could be also in Setup)
• Keyboard Shortcuts
• Setup WSL (for Windows)

Happy to hear other ideas for features that even intermediate users.