Add cloakhq/cloakbrowser Docker Hub image with Node.js, JS wrapper,
Xvfb headed mode, and cloaktest shortcut. Add launch feedback and IP
display to all examples. Update README Docker section for Docker Hub.
- Add launch_persistent_context() Python + JS with examples
- Document persistent context API in both READMEs
- Bump version to 0.3.5
- Credit @evelaa123 and @yahooguntu in CHANGELOG