fix prepublish hook

package.json

@@ -24,7 +24,7 @@
     "build": "npm run build:lib && npm run build:umd && npm run build:umd:min",
     "clean": "rimraf lib dist coverage doc",
     "lint": "eslint src test",
-    "prepublish": "npm run clean && npm run build",
+    "prepublish": "npm run clean && npm run build && npm run doc",
     "test": "mocha --compilers js:babel-register --recursive --require ./test/setup.js",
     "test:watch": "npm test -- --watch",
     "test:cov": "babel-node ./node_modules/isparta/bin/isparta cover ./node_modules/mocha/bin/_mocha -- --recursive"