Release .deb packages

[darkdragon-001]

Would be nice if you package your releases to make it easier to try out your program!

[dngray]

This shouldn't be difficult at all..

The instructions there https://github.com/glutanimate/PDFMtEd#overview-of-all-dependencies are a bit outdated too, as those dependencies are all now a part of Debian (no need for external repositories). Yad got a package in stretch/xenial and sejda is available in buster/bionic. @glutanimate maybe you'd like to update the README there.

[savchenko]

@glutanimate ,

Thank you for publishing an app. Would you consider uploading .deb for an upcoming Debian Bullseye?