docs: add circle ci badge to readme

Author: dherges

README.md

@@ -1,3 +1,16 @@
+Content-Driven Angular
+======================
+
+> Complete, narrative stories are published on [Spektrakel Blog @ medium.com](https://medium.com/spektrakel-blog/content-driven-angular/home)
+
+ 1. [Towards Content-Driven Angular Apps](https://medium.com/spektrakel-blog/towards-content-driven-angular-apps-67b7afd2dd8c)
+ 2. [Angular for the headless web — dynamic component rendering and content-driven apps](https://medium.com/spektrakel-blog/angular-for-the-headless-web-dynamic-component-rendering-and-content-driven-apps-803da730d324)
+
+---
+
+[![CircleCI](https://circleci.com/gh/spektrakel-blog/ng-content-driven-angular/tree/master.svg?style=svg)](https://circleci.com/gh/spektrakel-blog/ng-content-driven-angular/tree/master)
+
+
 ### Content Tree
 
 https://yuml.me/09e3fa25.json