readme: use ref style links

Author: robszumski

README.md

@@ -8,7 +8,10 @@ See the [design docs][design_docs] for planned work on upcoming milestones.
 
 ## Overview
 
-This project is a component of the [Operator Framework](https://github.com/operator-framework), an open source toolkit to manage Kubernetes native applications, called Operators, in an effective, automated, and scalable way. Read more in the [introduction blog post](https://coreos.com/blog/introducing-operator-framework).
+This project is a component of the [Operator Framework][of-home], an open source toolkit to manage Kubernetes native applications, called Operators, in an effective, automated, and scalable way. Read more in the [introduction blog post][of-blog].
+
+[of-home]: https://github.com/operator-framework
+[of-blog]: https://coreos.com/blog/introducing-operator-framework
 
 [Operators][operator_link] make it easy to manage complex stateful applications on top of Kubernetes. However writing an operator today can be difficult because of challenges such as using low level APIs, writing boilerplate, and a lack of modularity which leads to duplication.
 
@@ -78,4 +81,4 @@ To explore any operator samples built using the operator-sdk, see the [operator-
 [operator_link]: https://coreos.com/operators/
 [design_docs]: ./doc/design
 [guide]: ./doc/user-guide.md
-[samples]: https://github.com/operator-framework/operator-sdk-samples
+[samples]: https://github.com/operator-framework/operator-sdk-samples