Adding license text to src files, some descriptions. And small theming changes.

src/stage.rs

@@ -1,3 +1,23 @@
+    // <Kira Installer - universal Linux installer.>
+    // Copyright (C) <2026>  <Kira Foundation>
+
+    // This program is free software: you can redistribute it and/or modify
+    // it under the terms of the GNU General Public License as published by
+    // the Free Software Foundation, either version 3 of the License, or
+    // (at your option) any later version.
+
+    // This program is distributed in the hope that it will be useful,
+    // but WITHOUT ANY WARRANTY; without even the implied warranty of
+    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    // GNU General Public License for more details.
+
+    // You should have received a copy of the GNU General Public License
+    // along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+
+/*
+    This file contains basic enums and structs to be used with stages.
+ */
 
 use std::collections::HashMap;