Fix Javadoc generation on JDK 8.

core/src/main/java/hudson/AbstractMarkupText.java

@@ -72,8 +72,8 @@ public abstract class AbstractMarkupText {
      * Adds a start tag and end tag at the specified position.
      *
      * <p>
-     * For example, if the text was "abc", then <tt>addMarkup(1,2,"&lt;b>","&lt;/b>")</tt>
-     * would generate <tt>"a&lt;b>b&lt;/b>c"</tt>
+     * For example, if the text was "abc", then {@code addMarkup(1,2,"<b>","</b>")}
+     * would generate {@code"a<b>b</b>c"}
      */
     public abstract void addMarkup( int startPos, int endPos, String startTag, String endTag );