a11y modal

This is an implementation of a modal that is always focused when it is opened, preventing the Keyboard Trap.

TODO list:

• Create the modal button
• Create the modal itself
• Maintain a variable to keep track of the focused element before the modal opens
• Focus on the modal
• Keep track of the candidates to be the next focusable element (use querySelectorAll)
• Get the first and the last one of the above list
• If the user is on the last element and press tab, focus back to the first one
• If the user is on the first element and press shift + tab, focus to the last one
• If the user press esc, close the modal
• If the user clicks on the background, also close the modal
• Create the React version of it