Prevent breaked-lines in <p> (#404)

assets/_markdown.scss

@@ -87,6 +87,10 @@
     }
   }
 
+  p {
+    word-wrap:break-word;
+  }
+
   blockquote {
     margin: $padding-16 0;
     padding: $padding-8 $padding-16 $padding-8 ($padding-16 - $padding-4); //to keep total left space 16dp