Integrate npm package "doctoc" to update README.md

Author: PeterDaveHello

README.md

@@ -14,6 +14,8 @@ Still in the early stage, feel free to fork or contribute to HackMD.
 
 Thanks for using! :smile:
 
+<!-- START doctoc generated TOC please keep comment here to allow auto update -->
+<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
 # Table of Contents
 
 - [Browsers Requirement](#browsers-requirement)
@@ -35,6 +37,8 @@ Thanks for using! :smile:
   - [Operational Transformation](#operational-transformation)
 - [License](#license)
 
+<!-- END doctoc generated TOC please keep comment here to allow auto update -->
+
 # Browsers Requirement
 
 - Chrome >= 47, Chrome for Android >= 47

package.json

@@ -10,7 +10,8 @@
     "dev": "webpack --config webpack.config.js --progress --colors --watch",
     "build": "webpack --config webpack.production.js --progress --colors --bail",
     "postinstall": "bin/heroku",
-    "start": "node app.js"
+    "start": "node app.js",
+    "doctoc": "doctoc --title='# Table of Contents' README.md"
   },
   "dependencies": {
     "Idle.Js": "git+https://github.com/shawnmclean/Idle.js",
@@ -151,6 +152,7 @@
     "babel-runtime": "^6.20.0",
     "copy-webpack-plugin": "^4.0.1",
     "css-loader": "^0.26.1",
+    "doctoc": "^1.3.0",
     "ejs-loader": "^0.3.0",
     "exports-loader": "^0.6.3",
     "expose-loader": "^0.7.1",