Remove embedded demos

examples/password_manager_demo.py

@@ -0,0 +1,13 @@
+from password_manager.manager import PasswordManager
+from nostr.client import NostrClient
+
+
+def main() -> None:
+    """Show how to initialise PasswordManager with Nostr support."""
+    manager = PasswordManager()
+    manager.nostr_client = NostrClient(encryption_manager=manager.encryption_manager)
+    # Sample actions could be called on ``manager`` here.
+
+
+if __name__ == "__main__":
+    main()