Add. Post JSON example.

examples/cURLv3/post_json.lua

@@ -0,0 +1,12 @@
+local cURL = require "cURL"
+
+c = cURL.easy{
+  url        = "http://posttestserver.com/post.php",
+  post       = true,
+  httpheader = {
+    "Content-Type: application/json";
+  };
+  postfields = '{"hello": "world"}';
+}
+
+c:perform()