doc: use better wording to explain type-aware completion

Some editors can filter the autocompletion suggestions based on
whether the code will compile once autocompleted. Explain this
feature with better wording.

Change-Id: I29e4b0396878f18c79208915402c0a209a813b04
Reviewed-on: https://go-review.googlesource.com/53355Reviewed-by: Florin Patan <florinpatan@gmail.com>
Reviewed-by: Andrew Bonventre <andybons@golang.org>

doc/editors.html

@@ -65,7 +65,7 @@ The following feature matrix lists and compares the most significant features.
     <td class="yes">Yes</td>
   </tr>
   <tr>
-    <td>Autocompletion based on type</td>
+    <td>Type-aware autocompletion</td>
     <td class="no">No</td>
     <td class="no">No</td>
     <td class="yes">Yes</td>