A skip navigation link allows screen reader and keyboard-only users to
quickly skip the navigation menu. This one is visually hidden and
transitions in on focus. Helps site meet WCAG 2.0 SC 2.4.1 Bypass Blocks

Keyboard-only users need a visual indicator of focus when navigating a
page. This change meets WCAG 2.0 SC 2.4.7: Focus Visible.

removed dependency on Bootswatch flatly theme and repalced it wtih custom code, added a vendor directory so third party plugins are now separate from theme files

Updating Bootstrap and Bootswatch