feat: basically finish packer

packer/README.md

@@ -41,6 +41,9 @@ namespace_name = "foobar"
 target_name = "foobar"
 
 [package.metadata.omrf.pkgconfig]
+# The unique identifier of the package.
+# This property is optional; it defaults to the name of the target Rust project.
+id = "foobar"
 # Human-readable name of the package.
 # This property is optional; it defaults to the name of the target Rust project.
 name = "Foo Bar"