Update podman-kube-play.1.md.in

To avoid the error:
`Error: unable to read YAML as Kube Pod: error unmarshaling JSON: while decoding JSON: json: cannot unmarshal object into Go struct field Container.spec.containers.command of type string`

Also makes it easier to understand as you only need the image parameter.

Signed-off-by: Daskan <kevin81991@web.de>

docs/source/markdown/podman-kube-play.1.md.in

@@ -70,10 +70,7 @@ metadata:
 ...
 spec:
   containers:
-  - command:
-    - top
-    - name: container
-      value: podman
+  - name: container
     image: foobar
 ...
 ```
@@ -113,9 +110,7 @@ metadata:
   name: foobar
 spec:
   containers:
-  - command:
-    - top
-    name: container-1
+  - name: container-1
     image: foobar
     envFrom:
     - configMapRef:
@@ -145,9 +140,7 @@ metadata:
   name: foobar
 spec:
   containers:
-  - command:
-    - top
-    name: container-1
+  - name: container-1
     image: foobar
     env:
     - name: FOO