Document the fact that client must filter results from completion.results.

pkg/analysis_server/doc/api.html

Index: pkg/analysis_server/doc/api.html
diff --git a/pkg/analysis_server/doc/api.html b/pkg/analysis_server/doc/api.html
index b1195b18ea880d808bc0c33840d02adbe5a0708c..7175c95148ba6f72b609d491ea0bd5115b7dd490 100644
--- a/pkg/analysis_server/doc/api.html
+++ b/pkg/analysis_server/doc/api.html
@@ -961,7 +961,12 @@ dt.typeDefinition {
           </dd><dt class="field"><b><i>results ( List&lt;<a href="#type_CompletionSuggestion">CompletionSuggestion</a>&gt; )</i></b></dt><dd>
             
             <p>
-              The completion suggestions being reported.
+              The completion suggestions being reported.  The
+              notification contains all possible completions at the
+              requested cursor position, even those that do not match
+              the characters the user has already typed.  This allows
+              the client to respond to further keystrokes from the
+              user without having to make additional requests.
             </p>
           </dd><dt class="field"><b><i>last ( bool )</i></b></dt><dd>