Added captcha project

Author: ninjamar

data/projects.json

@@ -4,6 +4,11 @@
         "description": "A simple forwarding DNS Server",
         "url": "https://github.com/ninjamar/dns-server"
     },
+    {
+        "title": "Captcha",
+        "description: "Captcha system",
+        "url": "https://github.com/ninjamar/captcha"
+    },
     {
         "title": "2Tetris",
         "description": "Tetris, except you control two instances at once",