Add "jsonnet.d.ts" (#9394)

* Add "jsonnet.d.ts"

* fix comment

jsonnet/jsonnet-tests.ts

@@ -0,0 +1,6 @@
+/// <reference path="jsonnet.d.ts" />
+import Jsonnet = require('jsonnet');
+var jsonnet = new Jsonnet();
+var code = '{a:1}';
+var result = jsonnet.eval(code);
+console.log(result);

jsonnet/jsonnet.d.ts

@@ -0,0 +1,13 @@
+// Type definitions for jsonnet
+// Project: https://github.com/yosuke-furukawa/node-jsonnet
+// Definitions by: Hookclaw <https://github.com/hookclaw>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+declare module "jsonnet" {
+    class Jsonnet {
+        constructor();
+        eval(code: string): any;
+        evalFile(): any;
+        destroy(): void;
+    }
+    export = Jsonnet;
+}