Add example add content block query

client/src/graphql/gql/mutations/addContentBlock.gql

@@ -0,0 +1,28 @@
+mutation AddContentBlock($input: AddContentBlockInput!) {
+  addContentBlock(input: $input) {
+    newContentBlock {
+      id
+      title
+      slug
+      contents
+    }
+    clientMutationId
+  }
+}
+
+
+# input
+
+#{
+#  "input": {
+#    "contentBlock": {
+#      "title": "Hello World",
+#      "contents": [
+#        {
+#          "type": "text_block",
+#          "text": "<p>let's get <b>wild</b><script>alert(1)</script></p>"
+#        }
+#      ]
+#    }
+#  }
+#}