update deployment script for documentation

docs/.vuepress/dist/assets/img/search.83621669.svg

@@ -1 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?><svg xmlns="http://www.w3.org/2000/svg" width="12" height="13"><g stroke-width="2" stroke="#aaa" fill="none"><path d="M11.29 11.71l-4-4"/><circle cx="5" cy="5" r="4"/></g></svg>

package.json

@@ -27,7 +27,7 @@
     "build": "NODE_ENV=production react-scripts build",
     "test": "react-scripts test",
     "eject": "react-scripts eject",
-    "predeploy": "npm run build",
+    "predeploy": "npm run build && npm run docs:build",
     "deploy": "firebase deploy",
     "predeploy:app": "npm run build",
     "deploy:app": "firebase deploy --only hosting:app",
@@ -64,4 +64,4 @@
     "tailwindcss": "^1.2.0",
     "vuepress": "^1.4.0"
   }
-}
+}