Write 404 resolver for redirecting links

[SirLich]

This can wait until 1.1, since we will be doing a giant reorganization of the content, after the platform is complete.

[sermah]

A guide to create a custom 404 page for github pages

Probably 404.md needs to have permalink: 404.html in the top yaml thing

[SirLich]

This needs to keep as many old links as possible alive, by using js to redirect to a good page. For example:

https://wiki.bedrock.dev/documentation/biome-tags

Needs to become:

https://wiki.bedrock.dev/world-generation/biome-tags

[stirante]

Added a simple resolver to 404 page in 44feaa3

[SirLich]

Closing