Minor changes of doc

doc/dom.md

@@ -226,7 +226,7 @@ When the source encoding of stream is the same as encoding of DOM, by default, t
 
 Some techniques about using DOM API is discussed here.
 
-### DOM as SAX Event Publisher
+## DOM as SAX Event Publisher
 
 In RapidJSON, stringifying a DOM with `Writer` may be look a little bit weired.
 

doc/misc/doxygenextra.css

@@ -251,7 +251,7 @@ div.fragment {
 }
 
 /* external link icon */
-div #contents a[href ^= "http"]:after {
+div.contents a[href ^= "http"]:after {
      content: " " url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs+9AAAAVklEQVR4Xn3PgQkAMQhDUXfqTu7kTtkpd5RA8AInfArtQ2iRXFWT2QedAfttj2FsPIOE1eCOlEuoWWjgzYaB/IkeGOrxXhqB+uA9Bfcm0lAZuh+YIeAD+cAqSz4kCMUAAAAASUVORK5CYII=);
 }