Mention the author when quote-posting them

Fixes https://gitlab.com/soapbox-pub/soapbox/-/issues/1202

app/soapbox/reducers/compose.ts

@@ -319,10 +319,11 @@ export default function compose(state = initialState, action: AnyAction) {
       }));
     case COMPOSE_QUOTE:
       return updateCompose(state, 'compose-modal', compose => compose.withMutations(map => {
+        const author = action.status.getIn(['account', 'acct']);
         const defaultCompose = state.get('default')!;
 
         map.set('quote', action.status.get('id'));
-        map.set('to', ImmutableOrderedSet());
+        map.set('to', ImmutableOrderedSet([author]));
         map.set('text', '');
         map.set('privacy', privacyPreference(action.status.visibility, defaultCompose.privacy));
         map.set('focusDate', new Date());