Add horisontal scroll on table overflow (vuejs#793)

Author: ruskakimov

themes/vue/source/css/page.styl

@@ -103,6 +103,8 @@
         border-collapse collapse
         margin 1.2em auto
         padding 0
+        display block
+        overflow-x auto
         td, th
             line-height 1.5em
             padding .4em .8em