improve the 404 page automatically generated by NextJS

[barriebyron]

Describe the problem

the 404 page automatically generated by NextJS does not provide helpful context or next steps for zkApp developers

Describe the proposed solution

the 404 page is automatically generated by NextJS... but we can make it better. suggest providing helpful tips to help the developer move forward

• 404: Your zkApp UI cannot be loaded. Verify the repoURL is correct (and other things that cause the 404). See Tutorial 4 for required configuration.

(and whatever helpful messages can benefit our developer)

Alternatives considered

No response

Importance

would make my life easier

Additional Information

No response