add link to public-inbox to readme
bump zbus to version 4.3.1
don't assume protocols always mandate `//` path prefix
CLI implementation of xdg-desktop-portal client API
$ porta open-uri <uri>
$ porta file-chooser [optinal window title]
< returns selected filepaths >
submit them to my public-inbox by sending an email to ~robertgzr/public-inbox@lists.sr.ht