Add mobile hamburger menu(s)

app/assets/stylesheets/application.css

app/assets/stylesheets/application.tailwind.css

app/views/admin/conferences/import_history.html.erb

app/views/admin/conferences/index.html.erb

app/views/admin/conferences/show.html.erb

app/views/admin/dashboard/index.html.erb

app/views/admin/roles/_form.html.erb

app/views/admin/roles/edit.html.erb

app/views/admin/roles/index.html.erb

app/views/admin/users/index.html.erb

app/views/conferences/show.html.erb

app/views/layouts/application.html.erb

app/views/shared/_admin_nav.html.erb