Rename themes -> flavours ? ?

app/javascript/flavours/glitch/actions/local_settings.js

@@ -0,0 +1,24 @@
+export const LOCAL_SETTING_CHANGE = 'LOCAL_SETTING_CHANGE';
+
+export function changeLocalSetting(key, value) {
+  return dispatch => {
+    dispatch({
+      type: LOCAL_SETTING_CHANGE,
+      key,
+      value,
+    });
+
+    dispatch(saveLocalSettings());
+  };
+};
+
+//  __TODO :__
+//  Right now `saveLocalSettings()` doesn't keep track of which user
+//  is currently signed in, but it might be better to give each user
+//  their *own* local settings.
+export function saveLocalSettings() {
+  return (_, getState) => {
+    const localSettings = getState().get('local_settings').toJS();
+    localStorage.setItem('mastodon-settings', JSON.stringify(localSettings));
+  };
+};