Refactor Mobile Navigation to change UX to be a flyout from left

[brianravi]

Motivation

Ease of use on mobile devices

Details

Refactor the html nav structure in application.html.erb to support the mobile navigation seen here: https://get.foundation/ (shrink your screen width until mobile kicks in).

Tasks

• [ ] Add Flyout Menu using https://get.foundation/sites/docs/off-canvas.html
• [ ] place branding inside of flyout menu (logo and VHP name)
• [ ] Set menu items to be vertically stacked, similar to presentation on sample website above

Issue Chores

• [x] I have checked the VHP backlog for something similar: https://github.com/VulnerabilityHistoryProject/vulnerability-history/issues
• [x] I have checked if this should also be part of a Github Project: https://github.com/VulnerabilityHistoryProject/vulnerability-history/projects?type=beta
• [x] I have checked that this might need dev infrastructure or refactor labels