Add search input field labels using aria-label (#3046)

* Adding aria-label to search input on the search.html page
* Adding aria-label to the search input field for the search box

mkdocs/themes/readthedocs/search.html

@@ -6,7 +6,7 @@ <h1 id="search">{% trans %}Search Results{% endtrans %}</h1>
 
   <form id="content_search" action="search.html">
     <span role="status" aria-live="polite" class="ui-helper-hidden-accessible"></span>
-    <input name="q" id="mkdocs-search-query" type="text" class="search_input search-query ui-autocomplete-input" placeholder="{% trans %}Search the Docs{% endtrans %}" autocomplete="off" autofocus title="{% trans %}Type search term here{% endtrans %}">
+    <input name="q" id="mkdocs-search-query" type="text" class="search_input search-query ui-autocomplete-input" placeholder="{% trans %}Search the Docs{% endtrans %}" aria-label="{% trans %}Search the Docs{% endtrans %}" autocomplete="off" autofocus title="{% trans %}Type search term here{% endtrans %}">
   </form>
 
   <div id="mkdocs-search-results" class="search-results" data-no-results-text="{% trans %}No results found{% endtrans %}">

mkdocs/themes/readthedocs/searchbox.html

@@ -1,5 +1,5 @@
 <div role="search">
   <form id ="rtd-search-form" class="wy-form" action="{{ base_url }}/search.html" method="get">
-      <input type="text" name="q" placeholder="{% trans %}Search docs{% endtrans %}" title="{% trans %}Type search term here{% endtrans %}" />
+      <input type="text" name="q" placeholder="{% trans %}Search docs{% endtrans %}" aria-label="{% trans %}Search docs{% endtrans %}" title="{% trans %}Type search term here{% endtrans %}" />
   </form>
 </div>