Localize accessibility text in sidebar nav

Allow localizing labels used in the sidebar navigation to help
accessibility

Author: Tim Bannister

data/i18n/en/en.toml

@@ -597,6 +597,9 @@ other = "Changelog"
 [seealso_heading]
 other = "See Also"
 
+[sidebar_toggle_nav]
+other = "Toggle section navigation"
+
 [subscribe_button]
 other = "Subscribe"
 

layouts/partials/sidebar-tree.html

@@ -4,14 +4,14 @@
   {{ if not .Site.Params.ui.sidebar_search_disable -}}
   <form class="td-sidebar__search d-flex align-items-center">
     {{ partial "search-input.html" . }}
-    <button class="btn btn-link td-sidebar__toggle d-md-none p-0 ml-3 fas fa-bars" type="button" data-toggle="collapse" data-target="#td-section-nav" aria-controls="td-section-nav" aria-expanded="false" aria-label="Toggle section navigation">
+    <button class="btn btn-link td-sidebar__toggle d-md-none p-0 ml-3 fas fa-bars" type="button" data-toggle="collapse" data-target="#td-section-nav" aria-controls="td-section-nav" aria-expanded="false" aria-label="{{ T "sidebar_toggle_nav" }}">
     </button>
   </form>
   {{ else -}}
   <div id="content-mobile">
   <form class="td-sidebar__search d-flex align-items-center">
     {{ partial "search-input.html" . }}
-    <button class="btn btn-link td-sidebar__toggle d-md-none p-0 ml-3 fas fa-bars" type="button" data-toggle="collapse" data-target="#td-section-nav" aria-controls="td-section-nav" aria-expanded="false" aria-label="Toggle section navigation">
+    <button class="btn btn-link td-sidebar__toggle d-md-none p-0 ml-3 fas fa-bars" type="button" data-toggle="collapse" data-target="#td-section-nav" aria-controls="td-section-nav" aria-expanded="false" aria-label="{{ T "sidebar_toggle_nav" }}">
     </button>
   </form>
   </div>