Add environment files to gitignore.

.gitignore

@@ -47,3 +47,4 @@ Thumbs.db
 
 # Configuration Files
 .env
+src/environments/

README.md

@@ -36,6 +36,7 @@ Run `ng e2e` to execute the end-to-end tests via [Protractor](http://www.protrac
 
 Environment variables are contained in the `.env` file. See `.env.example` for a template.
 
+Default environment variables are set in the `set-env.ts` file.
 Once loaded they will be populated in the directory `src/environments/`.
 It contains environment variables for development on `environment.ts` and production on `environment.prod.ts`.