Add missing CMD argument in elasticsearch example

elasticsearch/README.md

@@ -26,7 +26,7 @@ You can run the default `elasticsearch` command simply:
 
 You can also pass in additional flags to `elasticsearch`:
 
-    docker run -it --rm elasticsearch -Des.node.name="TestNode"
+    docker run -it --rm elasticsearch elasticsearch -Des.node.name="TestNode"
 
 This image comes with a default set of configuration files for `elasticsearch`,
 but if you want to provide your own set of configuration files, you can do so

elasticsearch/content.md

@@ -16,7 +16,7 @@ You can run the default `elasticsearch` command simply:
 
 You can also pass in additional flags to `elasticsearch`:
 
-    docker run -it --rm elasticsearch -Des.node.name="TestNode"
+    docker run -it --rm elasticsearch elasticsearch -Des.node.name="TestNode"
 
 This image comes with a default set of configuration files for `elasticsearch`,
 but if you want to provide your own set of configuration files, you can do so