♻️ Major code restructuring

src/core.rs

@@ -0,0 +1,13 @@
+//! Key types and functions for creating actions, components, packages, and themes.
+
+// API to define functions that alter the behavior of PageTop core.
+pub mod action;
+
+// API to build new components.
+pub mod component;
+
+// API to add new features with packages.
+pub mod package;
+
+// API to add new layouts with themes.
+pub mod theme;