but i am pretty sure this stems from a time where we had non-ephemeral
non-automated account setup (regular testrun.org) and does not apply to chatmail.
* create a wwwdev.sh entry point for developing the web part
* rename script
* fix README
* add a note
* don't depend on deltachat python package
* avoid bailing out on jinja2 errors, and provide file-url for instant clickability
* in webdev mode make page auto-refresh every 3 seconds