Display a 404 page for non-existent pages

[jdnichollsc]

As a user, I want to see a clear indication when I try to access a page that doesn't exist on the site. This helps me understand that I have reached a dead end and need to navigate elsewhere.

Definition of Done:

• A 404 page has been designed and implemented
• The 404 page is displayed when a non-existent page is accessed
• The 404 page includes helpful information for the user, such as a search bar or links to other pages on the site
• The 404 page adheres to the site's branding guidelines

Tasks:

• Design and Implement the 404 page using TailwindCSS from a new route.
• Test the 404 page to ensure it is displayed correctly when a non-existent page is accessed
• Test the 404 page to ensure it includes helpful information for the user
• Test the 404 page to ensure it adheres to the site's branding guidelines