refactor: fix build

- by fixing the files/ directory migration
- and also updating the files module syntax
- and by copying configurations previously in /usr/etc/ to /etc/

generators/config/plasma.pkl

@@ -22,9 +22,10 @@ plasma = new Dynamic {
   }
   files = (modules.Files) {
     files = new Listing {
-      new Mapping<String, String> {
-        ["plasma"] = "/usr"
-      }
+        (modules.FilesListingItem) {
+            source = "system/plasma/"
+            destination = "/"
+        }
     }
   }
   scripts = (modules.Script) {

generators/config/shared.pkl

@@ -9,8 +9,9 @@ shared = new Dynamic {
   }
   files = (modules.Files) {
     files = new Listing {
-      new Mapping<String, String> {
-        ["shared"] = "/usr"
+      (modules.FilesListingItem) {
+        source = "system/shared/"
+        destination = "/"
       }
     }
   }

generators/typing/modules.pkl

@@ -26,9 +26,14 @@ class DefaultFlatpaks extends Module {
   user: DefaultFlatpaksNamespace
 }
 
+class FilesListingItem {
+    source: String
+    destination: String
+}
+
 class Files extends Module {
   fixed type: "files"
-  files: Listing<Mapping<String, String>>
+  files: Listing<FilesListingItem>
 }
 
 class Bling extends Module {