Fix jupyterlite config to include content by default

• Bump jupyterlite version to 1.2 and update dependencies
• Update README description to create a new JupyterLite and badge
• Update jupyterlite configuartion (to include favicon)
• Add example notebook in files/ folder

enabled an automatic merge when the pipeline for f24a065b succeeds

canceled the automatic merge

merged

mentioned in commit aaa406b5