fix(docs): use open library instead of openBrowser function (#266)

Author: tzmanics

README.md

@@ -163,13 +163,15 @@ See the [authenticating](https://www.netlify.com/docs/api/#authenticating) docs
 
 ```js
 // example:
+const open = require('open') // installed with 'npm i open'
+
 const login = async () => {
-  const ticket = await api.createTicket({
+  const ticket = await client.createTicket({
     clientId: CLIENT_ID,
   })
   // Open browser for authentication
-  await openBrowser(`https://app.netlify.com/authorize?response_type=ticket&ticket=${ticket.id}`)
-  const accessToken = await api.getAccessToken(ticket)
+  await open(`https://app.netlify.com/authorize?response_type=ticket&ticket=${ticket.id}`)
+  const accessToken = await client.getAccessToken(ticket)
   // API is also set up to use the returned access token as a side effect
   return accessToken // Save this for later so you can quickly set up an authenticated client
 }