Make it clear method and formmethod take "dialog" as value

Author: musgravejw

source

@@ -117965,8 +117965,10 @@ interface <dfn>External</dfn> {
      <th> <code data-x="">formmethod</code>
      <td> <code data-x="attr-fs-formmethod">button</code>;
           <code data-x="attr-fs-formmethod">input</code>
-     <td> HTTP method to use for <span>form submission</span>
-     <td> "<code data-x="">GET</code>"; "<code data-x="">POST</code>"
+     <td> Variant to use for <span>form submission</span>
+     <td> "<code data-x="">GET</code>";
+          "<code data-x="">POST</code>";
+          "<code data-x="">dialog</code>"
     <tr>
      <th> <code data-x="">formnovalidate</code>
      <td> <code data-x="attr-fs-formnovalidate">button</code>;
@@ -118164,7 +118166,7 @@ interface <dfn>External</dfn> {
     <tr>
      <th> <code data-x="">method</code>
      <td> <code data-x="attr-fs-method">form</code>
-     <td> HTTP method to use for <span>form submission</span>
+     <td> Variant to use for <span>form submission</span>
      <td> "<code data-x="attr-fs-method-GET-keyword">GET</code>";
           "<code data-x="attr-fs-method-POST-keyword">POST</code>";
           "<code data-x="attr-fs-method-dialog-keyword">dialog</code>"