add sidecar command examples and update codegen (#2825)

docs/administrator.md

@@ -1405,6 +1405,10 @@ configuration:
     volumeMounts:
     - mountPath: /custom-pgdata-mountpoint
       name: pgdata
+    env:
+      - name: "ENV_VAR_NAME"
+        value: "any-k8s-env-things"
+    command: ['sh', '-c', 'echo "logging" > /opt/logs.txt']
   - ...
 ```
 

docs/user.md

@@ -1005,6 +1005,7 @@ spec:
       env:
         - name: "ENV_VAR_NAME"
           value: "any-k8s-env-things"
+      command: ['sh', '-c', 'echo "logging" > /opt/logs.txt']
 ```
 
 In addition to any environment variables you specify, the following environment

pkg/apis/acid.zalan.do/v1/zz_generated.deepcopy.go

@@ -1277,6 +1277,11 @@ func (in *Sidecar) DeepCopyInto(out *Sidecar) {
 			(*in)[i].DeepCopyInto(&(*out)[i])
 		}
 	}
+	if in.Command != nil {
+		in, out := &in.Command, &out.Command
+		*out = make([]string, len(*in))
+		copy(*out, *in)
+	}
 	return
 }