refactor(docs-infra): remove unnecessary wrapper `<div>` from the "Cheat sheet" guide (#41051)

This commit removes an unnecessary wrapper `<div>` from the
"Cheat sheet" guide. The CSS styles that referenced the element's ID
(`#cheatsheet`) have been updated to use `.page-guide-cheatsheet`
instead.

PR Close #41051

aio/content/guide/cheatsheet.md

@@ -1,6 +1,5 @@
 <h1 class="no-toc">Cheat Sheet</h1>
 
-<div id="cheatsheet">
 <table class="is-full-width is-fixed-layout">
 <tbody><tr>
 <th>Bootstrapping</th>
@@ -391,4 +390,3 @@ so the <code>@Directive</code> configuration applies to components as well</p>
 </td>
 </tr>
 </tbody></table>
-</div>

aio/src/styles/2-modules/_code.scss

@@ -176,7 +176,7 @@ aio-code {
     padding: 4px;
   }
 
-  #cheatsheet {
+  .page-guide-cheatsheet & {
     td:first-of-type,
     th {
       code {

aio/src/styles/2-modules/_table.scss

@@ -81,7 +81,7 @@ table {
   }
 }
 
-#cheatsheet {
+.page-guide-cheatsheet {
 
   table tbody td {
     overflow: auto;