added docs to the repo

docs/_examples/bulk.asciidoc

@@ -0,0 +1,21 @@
+.Perform three operations in a single request
+[source,js]
+---------
+client.bulk({
+  body: [
+    // action description
+    { index:  { _index: 'myindex', _type: 'mytype', _id: 1 } },
+     // the document to index
+    { title: 'foo' },
+    // action description
+    { update: { _index: 'myindex', _type: 'mytype', _id: 2 } },
+    // the document to update
+    { doc: { title: 'foo' } },
+    // action description
+    { delete: { _index: 'myindex', _type: 'mytype', _id: 3 } },
+    // no document needed for this delete
+  ]
+}, function (err, resp) {
+  // ...
+});
+---------