add link to summary

also update doc:build script to build the site

build_scripts/build-doc-site.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+## get into the "build_scripts" folder regardless of the excution directory
+parent_path=$( cd "$(dirname "${BASH_SOURCE[0]}")" ; pwd -P )
+cd "$parent_path/.."
+
+## compile the doc
+node ./build_scripts/prebuild-doc.js
+gitbook build ./docs-src ./docs
+
+## push the doc into github
+git add ./docs
+git commit -m 'building docs'
+git push origin