Fix changelog markdown

Author: solsson

README.md

@@ -56,6 +56,7 @@ Then pick and chose from patches our [example variants](https://github.com/Yolea
 ## Version history
 
 | tag    | k8s ≥ | highlights  |
+| ------ | ----- | ----------- |
 | v7.0.0 | 1.15+ | [Breaking](https://github.com/Yolean/kubernetes-kafka/pull/311#issuecomment-657181714) with [nonroot](./nonroot/) and [native](./native/) bases |
 | v6.0.x | 1.13+ | Kafka [2.4.0](https://github.com/Yolean/kubernetes-kafka/pull/297) + [standard storage class](https://github.com/Yolean/kubernetes-kafka/pull/294) |
 | v6.0.0 | 1.11+ | Kafka 2.2.0 + `apply -k` (kubectl 1.14+) + [#270](https://github.com/Yolean/kubernetes-kafka/pull/270) |