R rose/skip to main on all pages

Description

Allow the user to click the "skip navigation" accessibility tab to bypass pressing the tab key multiple times to get to page content.

Functionality

User should be able to tab once when landing on the home page to focus and show a previously hidden "Skip to Main Link"
When the User Presses "Enter" or clicks the link the window will move and the target focus will move to the "skip-to-main" id.
The User's focus will then be off the navigation and into the content of the page.
User will have access to the "Skip to Main" link on all pages and will skip to where the "skip-to-main" id has been placed.

Related Issue

issue #359

Motivation and Context

Allows users who require the accessibility option to skip navigation to get to the page content.

How Has This Been Tested?

The skip navigation link was tested on all pages to ensure that the page moved to content as well as the focus being taken off the navigation for the user to tab through the page content.

Types of change

[x] New feature (non-breaking change which adds functionality)

Checklist:

[x] My code follows the code style of this project.
[ ] My change requires a change to the documentation.
[ ] I have updated the documentation accordingly.
[x] I have read the CONTRIBUTING document.
[ ] I have added tests to cover my changes.
[x] All new and existing tests passed.

Vets-Who-Code / vets-who-code-app

R rose/skip to main on all pages #417