deb: ensure universe is enabled on Ubuntu by default

Added apt source parser, module apt

src/lib.rs

@@ -3,6 +3,8 @@
 //! pkh allows working with Debian packages, with multiple actions/submodules
 #![deny(missing_docs)]
 
+/// Handle apt data (apt sources)
+pub mod apt;
 /// Build a Debian source package (into a .dsc)
 pub mod build;
 /// Parse or edit a Debian changelog of a source package