Updated README. #reviewthis @jwelshiv @tonydewan

README

@@ -1 +1,13 @@
-Reviewthis readme (that's a pun, by the way)
+Reviewthis readme (that's a pun, by the way)
+
+I am updating the docs so I can push a new commit with a review request. Stay tuned!
+
+Set your repo's Post-Receive hook to: http://reviewthis.heroku.com/
+
+If a commit message includes the hash #reviewthis, any github user
+(signified by @username) will get an email (if they have a public
+email address). Also, any email address includes gets an email as
+well.
+
+Currently, sendmail is used in dev, and since we're going to deploy
+to heroku, the sendgrid addon is used in production.