make spellcheck use all system locales

src/main/ipc.ts

@@ -4,7 +4,7 @@
  * Copyright (c) 2023 Vendicated and Vencord contributors
  */
 
-import { app, dialog, ipcMain, shell } from "electron";
+import { app, dialog, ipcMain, session, shell } from "electron";
 import { existsSync, readFileSync, watch } from "fs";
 import { open, readFile } from "fs/promises";
 import { join } from "path";
@@ -60,6 +60,14 @@ ipcMain.handle(IpcEvents.CLOSE, e => {
     e.sender.close();
 });
 
+ipcMain.handle(IpcEvents.SPELLCHECK_SET_LANGUAGES, (_, languages: string[]) => {
+    const ses = session.defaultSession;
+
+    const available = ses.availableSpellCheckerLanguages;
+    const applicable = languages.filter(l => available.includes(l)).slice(0, 3);
+    if (applicable.length) ses.setSpellCheckerLanguages(applicable);
+});
+
 ipcMain.handle(IpcEvents.SELECT_VENCORD_DIR, async () => {
     const res = await dialog.showOpenDialog(mainWin!, {
         properties: ["openDirectory"]