there is another mention of times in privacy.md,
however, there the gist is about that things are deleted,
it is fine if that happens earlier there (also it is not excluded).
targets discussion from https://github.com/chatmail/relay/pull/504
* 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
