Include a 'skip to main contents' link to improve accessibility

[HaSistrunk]

Is your feature request related to a problem? Please describe.

A skip link provides quick access to the main content of a page or view. This allows users navigating with a keyboard or other assistive tech to easily bypass repeated content like global site navigation.

Describe the solution you'd like

A "Skip to main contents" link that is visually hidden, but appears on focus and enables users to skip the main <nav>. Typically these appear in sites as the first focusable element (eg. open mutualaid.nyc and hit "tab"). See example markup in the A11y Style Guide.

Additional context

This accessibility guideline is specified in WCAG 2.x Level A (SC 2.4.1)

[HaSistrunk]

Flagging this issue as still outstanding.