🤖 chore: Add build-docs script.

These changes were automatically generated by a transform whose code can be found at:
  - https://github.com/make-github-pseudonymous-again/rejuvenate/blob/a44c42967442d65fd14272682fb84a6f32feb841/src/transforms/docs:build-setup.js
Please contact the author of the transform if you believe there was an error.

package.json

@@ -31,6 +31,7 @@
   ],
   "scripts": {
     "build": "babel --delete-dir-on-start --env-name production src -d lib",
+    "build-docs": "esdoc",
     "cover": "c8 --all --src src --reporter=lcov npm test",
     "dev": "npm run lint -- --fix && npm run cover -- -- -st --fail-fast",
     "esdoc": "esdoc",