Bugfix/#313 buggy cookie bar

[pleszkiewicz]

How to test these changes:

1. clone the repo
2. from the terminal go to the magic-script-components/website folder
3. run yarn install
4. run yarn start
5. documentation website should open in your default web browser
6. observe the cookie bar at the bottom of the page (the bar should be visible while you navigate through sub-pages and/or until you click Accept All Cookies button)

Closes #313 Closes #314