Update get-started.mdx

Author: flybayer

app/pages/docs/get-started.mdx

@@ -9,7 +9,7 @@ You need Node.js 12 or newer
 
 ### Install Blitz {#install-blitz}
 
-Run `npm install -g blitz`
+Run `yarn global add blitz` or `npm install -g blitz --legacy-peer-deps` (legacy-peer-deps is needed because npm totally change behavior of peer deps and some dependencies haven't caught up)
 
 ### Create a New App {#create-a-new-app}