chore: submodule-notes

Author: Preeternal

.gitignore

@@ -90,4 +90,7 @@ nitrogen/
 .github/copilot-instructions.md
 
 # Example
-example/ios/FileHashExample.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings
+example/ios/FileHashExample.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings
+
+# Local notes
+submodule-notes.md