fix(vite): conditional notes

Author: NathanWalker

content/configuration/vite.md

@@ -179,7 +179,7 @@ We define a few useful globally available variables that you can use to alter lo
   ```
 - `__ANDROID__`, `true` when the platform is Android
   ```ts
-  if (global.isAndroid) {
+  if (__ANDROID__) {
     // we are running on android
   }
   ```
@@ -189,6 +189,12 @@ We define a few useful globally available variables that you can use to alter lo
     // we are running on iOS
   }
   ```
+- `__VISIONOS__`, `true` when the platform is visionOS
+  ```ts
+  if (__VISIONOS__) {
+    // we are running on visionOS
+  }
+  ```
 
 ::: details The following variables are also defined, but are primarily intended to be used by NativeScript Core internally, or plugins that wish to use these.