Port `From Express.js to h3` to v2 docs

[GeoffreyParrier]

Describe the change

In v1 docs there was an example docs comparing Express.js and h3 and it's missing from v2 docs.

Will it be added when v2 became stable?

URLs

https://v1.h3.dev/examples/from-expressjs-to-h3

Additional information

• [ ] Would you be willing to help?