Add note that updateText can have rangeStart > rangeEnd (#90)

Per discussion in #81, add note clarifying that updateStart() can have updateRangeStart > updateRangeEnd.
Replace old note that doesn't seem to apply anymore.

Closes #81

index.html

@@ -1035,9 +1035,7 @@ <h3 id="editcontext-interface">EditContext Interface</h3>
                 <ol>
                     <li>
                         Replace the substring of [=text=] in the range of |rangeStart| and |rangeEnd| with |newText|
-                    </li>
-                    <li>
-                        <div class="note">Add details regarding rangeStart/rangeEnd vs. [=selection start=]/[=selection end=]</div>
+                        <div class="note">It's permissible that |rangeStart| > |rangeEnd|. The substring between the indices should be replaced in the same way as when |rangeStart| <= |rangeEnd|.</div>
                     </li>
                 </ol>
             </div>