[Index] Add GM class to body

CHANGELOG.md

@@ -4,6 +4,7 @@
 
   - ### Themeability
     - **GooseMod settings sidebar items now have easier ids to grab.** Used to just use label so was reliant on supporting all translations.
+    - **Added GooseMod class to body so themes know if it's in use.**
 
 
 ## v12.0 [2021-08-26]

src/index.js

@@ -242,6 +242,8 @@ const init = async function () {
 
 
   ProfileStoreInit();
+
+  document.body.classList.add('goosemod'); // Add goosemod class to body for themes
 };
 
 window.goosemod = {};