nothing should happen inside the (overlay) sidebar when it is not open. because this creates history items for no reason and creates loads of unnecessary requests
the (overlay) sidebar should not inherit css from the website it is in. In order to prevent that, I wrapped it into a shadowDOM
as a small extra, the (overlay) sidebar is now resizable and it can be moved to the right side: just like the native sidebar
I am trying to address #59 and #60: