docs: using hono/csrf middleware

[benjamine]

just a documentation update.
updating hono guide to use the built-in hono/csrf middleware, see https://hono.dev/middleware/builtin/csrf

[pilcrowonpaper]

Can you update this line

This can be easily done by comparing the Origin and Host header.

to something like

This can be done using the csrf() middleware provided by Hono.

[benjamine]

@pilcrowonpaper good catch, just updated the text above

[pilcrowonpaper]

Thanks!