use canonical module subfolder tree

src/browser/header/subject/mod.rs

@@ -0,0 +1,20 @@
+mod description;
+mod title;
+
+use gtk::prelude::BoxExt;
+use gtk::Box;
+
+pub fn new() -> Box {
+    let subject = Box::builder()
+        // Tuneup
+        .orientation(gtk::Orientation::Vertical)
+        .valign(gtk::Align::Center)
+        .build();
+
+    // Compose childs
+    subject.append(&title::new());
+    subject.append(&description::new());
+
+    // Done
+    subject
+}