readme changes for efp. do not merge until 11/28 (#66)

Co-authored-by: Jonathan McAllister <[email protected]>

Author: Jonathan McAllister

README.md

@@ -6,6 +6,12 @@ This application supports the [Getting Started with PHP on Heroku](https://devce
 
 ## Deploying
 
+Using resources for this example app counts towards your usage. [Delete your app](https://devcenter.heroku.com/articles/heroku-cli-commands#heroku-apps-destroy) and [database](https://devcenter.heroku.com/articles/heroku-postgresql#removing-the-add-on) as soon as you are done experimenting to control costs.
+
+By default, apps use Eco dynos if you are subscribed to Eco. Otherwise, it defaults to Basic dynos. The Eco dynos plan is shared across all Eco dynos in your account and is recommended if you plan on deploying many small apps to Heroku. Learn more about our low-cost plans [here](https://blog.heroku.com/new-low-cost-plans).
+
+Eligible students can apply for platform credits through our new [Heroku for GitHub Students program](https://blog.heroku.com/github-student-developer-program).
+
 Install the [Heroku Toolbelt](https://toolbelt.heroku.com/).
 
 ```sh