VSCode

• display a Markdown syntax preview pane? - ctrl+k v
  • Markdown All in One
  • Markdown Preview Enhanced

Images

• Adding images and links to files to Markdown in VS Code - press shift & drag from image file

Runner

• Markdown Command Runner - When clicked the associated snippet is run the current active terminal or a new one if it is busy.
• Run your README.md like a notebook in VS Code

see also

• The Ultimate Guide to Writing a Great README.md for Your Project