fixed mobile layout bug

Author: jdkunesh

_layouts/page.html

@@ -1,7 +1,7 @@
 ---
 layout: default
 main:
-  class: usa-grid usa-section usa-content usa-layout-docs
+  class: usa-grid usa-section usa-content
 ---
 {% assign sidenav = site.data.navigation[page.sidenav] | default: page.sidenav %}
 {% if sidenav %}