Merge pull request #187 from perlun/patch-2

README.md: Added note about sourcemaps/tsconfig.json

Author: chriskrycho

README.md

@@ -100,6 +100,9 @@ const app = new EmberApp(defaults, {
 
 (Note that this _will_ noticeably slow down your app rebuilds.)
 
+If you're updating from an older version of the addon, you may also need to update your `tsconfig.json`. (Current versions generate the correct config at installation.) Either run
+`ember generate ember-cli-typescript` or verify you have the same sourcemap settings in your `tscsonfig.json` that appear in [the blueprint](https://github.com/typed-ember/ember-cli-typescript/blob/master/blueprints/ember-cli-typescript/files/tsconfig.json).
+
 ## Using TypeScript with Ember effectively
 
 In addition to the points made below, you may find the [Typing Your Ember][typing-your-ember] blog series (especially the "Update" sequence) particularly helpful in knowing how to do specific things.