[Authentication] Add mention of better-auth library support for Hono

[websharkdev]

I'd like to suggest updating the documentation to include information about better-auth, a new authentication library that supports Hono. This library simplifies various authentication aspects and could be valuable for developers looking for modern and efficient solutions. Adding this to the documentation would help users discover and integrate it easily.

Reason: better-auth is one of the newest libraries that enhances the development experience by simplifying common authentication processes. Highlighting it in the documentation will inform users of this powerful alternative and expand their options.

better-auth

[yusukebe]

Hi @websharkdev thank you for creating the issue.

Seems to be good! You can add the page about Better Auth with Hono in the Examples section on our website.