Work in progress language selection support

Still need to add a popup telling you that NUSGet needs to be restarted after changing the language, and having it load the selected language in the selection menu so that it's checked on launch.

modules/config.py

@@ -0,0 +1,27 @@
+# "modules/config.py", licensed under the MIT license
+# Copyright 2024-2025 NinjaCheetah & Contributors
+
+import os
+import json
+import pathlib
+
+def get_config_file() -> pathlib.Path:
+    config_dir = pathlib.Path(os.path.join(
+        os.environ.get('APPDATA') or
+        os.environ.get('XDG_CONFIG_HOME') or
+        os.path.join(os.environ['HOME'], '.config'),
+        "NUSGet"
+    ))
+    config_dir.mkdir(exist_ok=True)
+    return config_dir.joinpath("config.json")
+
+
+def save_config(config_data: dict) -> None:
+    config_file = get_config_file()
+    print(f"writing data: {config_data}")
+    open(config_file, "w").write(json.dumps(config_data, indent=4))
+
+
+def update_setting(config_data: dict, setting: str, value: any) -> None:
+    config_data[setting] = value
+    save_config(config_data)