add expandable plugin

uidoc/book.json

@@ -2,7 +2,8 @@
     "plugins": [
         "jsfiddle",
         "splitter",
-        "theme-api"
+        "theme-api",
+        "expandable-chapters"
     ],
     "pluginsConfig": {
         "theme-default": {
@@ -18,6 +19,7 @@
             "height": "100",
             "width": "500",
             "fontColor": "00FF00"
-        }
+        },
+        "expandable-chapters":{}
     }
 }

uidoc/package.json

@@ -22,6 +22,7 @@
   "devDependencies": {
     "gh-pages": "^1.0.0",
     "gitbook-cli": "^2.3.2",
+    "gitbook-plugin-expandable-chapters": "^0.2.0",
     "gitbook-plugin-jsfiddle": "^1.0.0",
     "gitbook-plugin-splitter": "0.0.8",
     "gitbook-plugin-theme-api": "^1.1.2",