build(package): simplify repository fields

created using @octoherd and https://github.com/gr2m/octoherd-script-normalize-package-repository-field

Author: gr2m

package.json

@@ -11,7 +11,7 @@
     "start": "node cli.js",
     "test": "node script.js"
   },
-  "repository": "https://github.com/octoherd/script-hello-world",
+  "repository": "github:octoherd/script-hello-world",
   "keywords": [
     "octoherd-script"
   ],