Update app/materials_library.py

app/materials_library.py

@@ -1391,7 +1391,7 @@ def display_materials_help():
     **Materials Tab:**
     
     * **Library Materials**: Pre-defined materials with standard thermal properties. Use 'Preview' to view details or 'Copy' to add to your project.
-    * **Project Materials**: Materials you've added to your project. Use 'Edit' to modify or 'Delete' to remove.
+    * **Project Materials**: Materials you have added to your project. Use 'Edit' to modify or 'Delete' to remove.
     * **Material Editor/Creator**: Create new materials or edit existing project materials. Library materials can only be previewed.
     
     **Fenestrations Tab:**