Add skip-to-content button

[SaptakS]

Usuall it's a good practise to add a skip-to-content link at the very beginning of the page that is visible only in tab-navigation. This allows keyboard users to skip the navigation links and jump to the content of the page. We don't have a super long list of navigation, so I won't say it's absolutely necessary, but still a good to have.

Implementation: https://css-tricks.com/how-to-create-a-skip-to-content-link/