Update grid class fot td-sidebar-toc to use all the available space.

The screen is divided into 12 columns, the existing layout was
only using 10.  Updated toc (where the taxonomy lives) to use
the remaining 2 columns.

Author: stumbo

layouts/bibliography/baseof.html

@@ -13,7 +13,7 @@
     <div class="container-fluid td-outer">
       <div class="td-main" {{- .Section | safeHTMLAttr }}>
         <div class="row flex-xl-nowrap">
-          <aside class="d-none d-xl-block col-xl-2 td-sidebar-toc d-print-none">
+          <aside class="d-none d-xl-block col-xl-4 td-sidebar-toc d-print-none">
             {{ partial "page-meta-links.html" . }}
             {{ partial "toc.html" . }}
             {{ partial "taxonomy_terms_clouds.html" . }}