add script to generate dereferenced schema

Author: jonathanmorley

package-lock.json

@@ -5,6 +5,7 @@
   "repository": "https://github.com/github/safe-settings.git",
   "main": "index.js",
   "scripts": {
+    "build:schema": "./script/build-schema",
     "dev": "nodemon --inspect",
     "start": "probot run ./index.js",
     "test": "npm-run-all --print-label --parallel lint:* --parallel test:*",
@@ -23,6 +24,7 @@
   "author": "Yadhav Jayaraman",
   "license": "ISC",
   "dependencies": {
+    "@apidevtools/json-schema-ref-parser": "^11.7.2",
     "@probot/adapter-aws-lambda-serverless": "^3.0.2",
     "deepmerge": "^4.3.1",
     "eta": "^3.0.3",