add 3 kinds of buttons to open toc content

exampleSite/config.toml

@@ -37,10 +37,12 @@ displayDate = true
 selectable = true
 # Custom global font. notice: `globalFontFamily` won't be working
 # on texts in some special positions like on titles
-globalFontFamily = 'Helvatica sans-serif'
+globalFontFamily = 'LXGW WenKai'
 # If set true, all your posts will use the chosen comment plugin
 # except those with a `comment: false` in their front-matter
 commentOnAllPosts = false
+# toc decides the shape of the toc button. e.g. default, lines, bar
+toc = "lines"
 
 # Disqus configuration
 [params.disqus]