added dependencies

vendor/twbs/bootstrap/site/layouts/partials/skippy.html

@@ -0,0 +1,8 @@
+<div class="skippy overflow-hidden">
+  <div class="container-xl">
+    <a class="sr-only sr-only-focusable d-inline-flex p-2 m-1" href="#content">Skip to main content</a>
+    {{ if (eq .Page.Layout "docs") -}}
+    <a class="sr-only sr-only-focusable d-none d-md-inline-flex p-2 m-1" href="#bd-docs-nav">Skip to docs navigation</a>
+    {{- end }}
+  </div>
+</div>