Updated hiring links

- Ghost is still hiring, but we've split our product engineer into two and the URL has changed

.github/PULL_REQUEST_TEMPLATE.md

@@ -6,7 +6,7 @@ Please include a description of your change & check your PR against this list, t
 - [ ] Commit message has a short title & references relevant issues
 - [ ] The build will pass (run `yarn test:all` and `yarn lint`)
 
-We appreciate your contribution! 
+We appreciate your contribution!
 
 Also, if you'd be interested in writing code like this for us more regularly, we're hiring:
-https://careers.ghost.org/product-engineer-node-js
+https://careers.ghost.org

README.md

@@ -30,7 +30,7 @@
     </a>
 </p>
 <p align="center">
-  Love open source? <a href="https://careers.ghost.org/product-engineer-node-js/">We're hiring</a> Node.js engineers to work on Ghost full-time.
+  Love open source? <a href="https://careers.ghost.org">We're hiring</a> JavaScript engineers to work on Ghost full-time.
 </p>
 
 &nbsp;