Editorial: add contenteditable enumerated attribute table

Helps with #9832

source

@@ -80288,19 +80288,42 @@ addShortcutKeyLabel(document.getElementById('c'));</code></pre>
 
   <p>The <dfn element-attr for="html-global"><code
   data-x="attr-contenteditable">contenteditable</code></dfn> content attribute is an
-  <span>enumerated attribute</span> whose keywords are the empty string, <code
-  data-x="">true</code>, <code data-x="">plaintext-only</code> and <code data-x="">false</code>.
-  The empty string and the <code data-x="">true</code> keyword map to the <i>true</i> state.
-  The <code data-x="">plaintext-only</code> keyword maps to the <i>plaintext-only</i> state.
-  The <code data-x="">false</code> keyword maps to the <i>false</i> state. In addition, there is a
-  fourth state, the <i>inherit</i> state, which is the <i data-x="missing value default">missing
-  value default</i> and <i data-x="invalid value default">invalid value default</i>.</p>
+  <span>enumerated attribute</span> with the following keywords and states:</p>
 
-  <p>The <i>true</i> state indicates that the element is editable. The <i>plaintext-only</i> state
-  indicates that only the element's raw text content is editable, but rich text formatting is
-  disabled. The <i>inherit</i> state indicates that the element is the same kind of editable (or
-  not editable) as the parent element. The <i>false</i> state indicates that the element is not
-  editable.</p>
+  <table>
+   <thead>
+    <tr>
+     <th>Keyword
+     <th>State
+     <th>Brief description
+   <tbody>
+    <tr>
+     <td><dfn attr-value for="html-global/contenteditable"><code
+     data-x="attr-contenteditable-true">true</code></dfn>
+     <td rowspan=2><dfn data-x="attr-contenteditable-true-state">true</dfn>
+     <td rowspan=2>Indicates the element is editable.
+    <tr>
+     <td>(The empty string)
+    <tr>
+     <td><dfn attr-value for="html-global/contenteditable"><code
+     data-x="attr-contenteditable-false">false</code></dfn>
+     <td><dfn data-x="attr-contenteditable-false-state">false</dfn>
+     <td>The element is not editable.
+    <tr>
+     <td><dfn attr-value for="html-global/contenteditable"><code
+     data-x="attr-contenteditable-plaintextonly">plaintext-only</code></dfn>
+     <td><dfn data-x="attr-contenteditable-plaintextonly-state">plaintext-only</dfn>
+     <td>Only the element's raw text content is editable, rich formatting is disabled.
+    <tr>
+     <td>
+     <td><dfn data-x="attr-contenteditable-inherit-state">inherit</dfn>
+     <td>The element is editable (or not) based on the parent element's state.
+  </table>
+
+
+  <p>The attribute's <i data-x="missing value default">missing value default</i> and <i
+  data-x="invalid value default">invalid value default</i> are both the <span
+  data-x="attr-contenteditable-inherit-state">inherit</span> state.</p>
 
   <div class="example">
    <p>For example, consider a page that has a <code>form</code> and a <code>textarea</code> to