add role="tabpanel" to .panel-collapse to improve accessibility

Refs #13555.
Per https://github.com/paypal/bootstrap-accessibility-plugin/blob/master/README.md#collapse
Credit: https://github.com/paypal/bootstrap-accessibility-plugin

[skip sauce]

diff --git a/docs/_includes/js/collapse.html b/docs/_includes/js/collapse.html
index e878cdb091ae0c99fb9f78bf5b8cb622ad252875..1a09aea9b074319a28b7d584395f578726a3ea99 100644 (file)
--- a/docs/_includes/js/collapse.html
+++ b/docs/_includes/js/collapse.html
@@ -22,7 +22,7 @@
             </a>
           </h4>
         </div>
-        <div id="collapseOne" class="panel-collapse collapse in">
+        <div id="collapseOne" class="panel-collapse collapse in" role="tabpanel">
           <div class="panel-body">
             Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
           </div>
@@ -36,7 +36,7 @@
             </a>
           </h4>
         </div>
-        <div id="collapseTwo" class="panel-collapse collapse">
+        <div id="collapseTwo" class="panel-collapse collapse" role="tabpanel">
           <div class="panel-body">
             Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
           </div>
@@ -50,7 +50,7 @@
             </a>
           </h4>
         </div>
-        <div id="collapseThree" class="panel-collapse collapse">
+        <div id="collapseThree" class="panel-collapse collapse" role="tabpanel">
           <div class="panel-body">
             Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
           </div>
@@ -68,7 +68,7 @@
         </a>
       </h4>
     </div>
-    <div id="collapseOne" class="panel-collapse collapse in">
+    <div id="collapseOne" class="panel-collapse collapse in" role="tabpanel">
       <div class="panel-body">
         Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
       </div>
@@ -82,7 +82,7 @@
         </a>
       </h4>
     </div>
-    <div id="collapseTwo" class="panel-collapse collapse">
+    <div id="collapseTwo" class="panel-collapse collapse" role="tabpanel">
       <div class="panel-body">
         Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
       </div>
@@ -96,7 +96,7 @@
         </a>
       </h4>
     </div>
-    <div id="collapseThree" class="panel-collapse collapse">
+    <div id="collapseThree" class="panel-collapse collapse" role="tabpanel">
       <div class="panel-body">
         Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
       </div>