Enhancement - annotation substitution

- Annotations are now modifiable using the /from/to/ modification
  command.

html/advanced.html

@@ -312,6 +312,11 @@ ID Project Pri Description
                   This command makes single corrections to a task description.
                 </p>
 
+                <p>
+                  If a task is annotated, the annotation can be modified using
+                  this command.
+                </p>
+
                 <strong>% task tags</strong>
                 <p>
                   This command will generate a list of all the tags that are currently

html/task.html

@@ -144,6 +144,7 @@
                   <li>Fixed bug that caused recurring annual tasks to exhibit a creeping due
                       date, because of an assumption of 365 days per year, which failed to
                       consider leap years (thanks to T. Charles Yun).
+                  <li>Annotations can now be modified with the substitution commands /from/to/.
                 </ul>
 
                 <p>