Ignore local package-lock.json stub

generalFunctions has no production deps of its own, so any
package-lock.json found here is a stub from a stray `npm install`
inside the submodule directory. Don't track it.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,5 @@
+node_modules/
+
+# Local stub generated by `npm install` in the submodule directory.
+# generalFunctions has no production deps of its own.
+package-lock.json