Direct to all in one page for search (#131)

* remove search-form from header

* add aio link

* hard label search

* change search to button

* remove list formatting

* make button text descriptive

* Update inst/pkgdown/templates/header.html

Make "Search in this lesson's "all in one" page" translatable.

* only show search for not overview

inst/pkgdown/templates/header.html

@@ -181,6 +181,7 @@
         {{/more}}
       </ul>
     </div>
+    <!--
     <form class="d-flex col-md-2 search-form">
       <fieldset disabled>
       <input class="form-control me-2 searchbox" type="search" placeholder="{{ translate.Search }}" aria-label="{{ translate.Search }}">
@@ -189,6 +190,10 @@
         </button>
       </fieldset>
     </form>
+    -->
+    {{^overview}}
+    <a class="btn btn-primary" href="{{#site}}{{root}}{{/site}}aio.html" role="button">{{ translate.SearchButton }}</a>
+    {{/overview}}  
   </div><!--/div.container-fluid -->
 </nav>