Update PR template

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,5 +1,5 @@
-!!!!! STOP AND READ !!!!!
+<!--
+⚠️ 🚨 ⚠️  STOP AND READ THIS ⚠️ 🚨 ⚠️
 
-If the dropdown above says "base fork: lord/master", you are submitting your change to ALL USERS OF SLATE, not just your company. This is probably not what you want. Click "base fork" to change it to the right place.
-
-If you're actually trying to submit a change to upstream Slate, please submit to our dev branch, PRs sent to the master branch are generally rejected.
+👆👆 see that 'base fork' dropdown above? You should change it! The default value of "lord/slate" submits your change to ALL USERS OF SLATE, not just your company. This is PROBABLY NOT WHAT YOU WANT.
+-->