Add logo to header of README (hashicorp#1028)

* Add logo to header of README

* Update README.md

Co-authored-by: David Yu <[email protected]>

Co-authored-by: David Yu <[email protected]>

Author: Thomas Eckert

README.md

@@ -1,4 +1,7 @@
-# Consul + Kubernetes (consul-k8s)
+<h1>
+  <img src="./assets/logo.svg" align="left" height="46px" alt="Consul logo"/>
+  <span>Consul on Kubernetes</span>
+</h1>
 
  **We're looking for feedback on how folks are using Consul on Kubernetes. Please fill out our brief [survey](https://hashicorp.sjc1.qualtrics.com/jfe/form/SV_4MANbw1BUku7YhL)!**