Add CONTRIBUTING.md - general instruction for contributors

package.json

@@ -190,6 +190,7 @@
   ],
   "scripts": {
     "build": "./script/build-dist.sh && ./script/build-module.js",
+    "build+test": "npm run build && npm run test",
     "fuzz": "jazzer ./test/jazzer-fuzz-test.js --sync",
     "test": "./script/test-all.sh",
     "test:eslint": "eslint src && eslint script",