openeo doc tweaks

Author: rconway

docs/building-blocks/openeo-engine.md

@@ -43,8 +43,9 @@ Take a look at the [values.yaml](https://github.com/kubeflow/spark-operator/blob
 
 #### ZooKeeper
 
-openEO uses [Apache ZooKeeper](https://zookeeper.apache.org/) under the hood. To get a basic ZK installed in your cluster, follow these steps:<br>
-_Note use of variables `${...}` that should be substituted with appropriate values_
+openEO uses [Apache ZooKeeper](https://zookeeper.apache.org/) under the hood. To get a basic ZK installed in your cluster, follow these steps:
+
+> _Note use of variables `${...}` that should be substituted with appropriate values_
 
 ```bash
 helm upgrade -i openeo-geotrellis-zookeeper zookeeper \
@@ -79,8 +80,10 @@ helm upgrade -i openeo-geotrellis-openeo sparkapplication \
     --values values.yaml
 ```
 
-Example `values.yaml` file:<br>
-_Note use of variables `${...}` that should be substituted with appropriate values_
+Example `values.yaml` file:
+
+> _Note use of variables `${...}` that should be substituted with appropriate values_
+
 ```yaml
 ---
 image: eoepca/openeo-geotrellis-kube
@@ -316,6 +319,8 @@ helm upgrade -i openeofed openeo-aggregator \
 
 An example `values.yaml` file:
 
+> _Note use of variables `${...}` that should be substituted with appropriate values_
+
 ```yaml
 ---
 configMaps: