Update installation.mdx (#4013)

Update yarn command to install nextui-cli because yarn add -g ... doesnt work and needs to use yarn add global

Author: clementvt

apps/docs/content/docs/guide/installation.mdx

@@ -26,7 +26,7 @@ Execute one of the following commands in your terminal:
 <PackageManagers
   commands={{
     npm: "npm install -g nextui-cli",
-    yarn: "yarn add -g nextui-cli",
+    yarn: "yarn add global nextui-cli",
     pnpm: "pnpm add -g nextui-cli",
     bun: "bun add -g nextui-cli",
   }}