Provided a simple example in the documentation to orient new users.

Author: AidanDelaney

README.md

@@ -15,3 +15,31 @@ bower install purescript-argonaut-codecs
 ## Documentation
 
 Module documentation is [published on Pursuit](http://pursuit.purescript.org/packages/purescript-argonaut-codecs).
+
+## Example
+
+Using [purescript-argonaut-core](https://github.com/purescript-contrib/purescript-argonaut-core) we can build a simple `Json` object:
+
+```purescript
+someObject = fromObject (StrMap.fromFoldable [
+                Tuple "foo" (fromArray [
+                  jsonSingletonObject "bar" (fromString "a"),
+                  jsonSingletonObject "bar" (fromString "b")
+                ])
+              ])
+```
+
+The `decodeJson` and `.?` functions provided in this module make it straightforward to interrogate the `Json` object:
+
+```purescript
+main =
+  log $ show $ getBars someObject
+
+getBars :: Json -> Either String (Array String)
+getBars json = do
+  obj <- decodeJson json
+  foo <- obj .? "foo"
+  for foo \itemJson -> do
+    itemObj <- decodeJson itemJson
+    itemObj .? "bar"
+```