Global navigation sidebar

Goal

Add a global navigation sidebar to the left side of the site template, allowing browsing to other site sections as well as within the current section.

MVC

First iteration: https://gitlab.com/gitlab-com/gitlab-docs/merge_requests/362

• Create the nav logic
• Position the nav on the page
• Add .active class to identify each page of the global nav the reader is at
• Position everything on the pages (the 3 columns of the page: global nav | content | ToC)
• Hide the global nav on mobile for the MVC and implement a toggle for mobile in further iterations

Current state of the MVC: