introduce workspace

crates/core/src/backend/mod.rs

@@ -0,0 +1,17 @@
+mod actual;
+mod backend_trait;
+mod iter;
+mod macros;
+mod todo_per_backend;
+
+pub(crate) use backend_trait::Backend;
+pub(crate) use iter::BackendIter;
+pub(crate) use todo_per_backend::ToDoPerBackend;
+
+use ::macros::Register;
+
+#[derive(Debug, Register)]
+pub(crate) enum Backends {
+    Pacman,
+    Rust,
+}