Document bindings (#119)

* Instructions for WASM/JS binding

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

* Document Python, WASM/JS bindings

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

---------

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

bindings/wasm/test.js

@@ -0,0 +1,47 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+var regorus = require('./pkg/regorusjs')
+
+// Create an engine.
+var engine = new regorus.Engine();
+
+// Add Rego policy.
+engine.add_policy(
+    // Associate this file name with policy
+    'hello.rego',
+    
+    // Rego policy
+`
+  package test
+  
+  # Join messages
+  message = concat(", ", [input.message, data.message])
+`)
+
+// Set policy data
+engine.add_data_json(`
+ {
+    "message" : "World!"
+ }
+`)
+
+// Set policy input
+engine.set_input_json(`
+ {
+	"message" : "Hello"
+ }
+`)
+
+// Eval query
+results = engine.eval_query('data.test.message')
+
+// Display
+console.log(results)
+
+// Convert results to object
+results = JSON.parse(results)
+
+// Process result
+console.log(results.result[0].expressions[0].value)
+