Wrong redirect

[allevo]

The redirection should be made with an absolute url and redirect to /documentation/index.html

https://github.com/fastify/fastify-swagger/blob/master/routes.js#L10

[mcollina]

+1! PR?

[sjorsjes]

This also prevents us from using this in the root of a project. I want mine to be on
http://localhost:3000 but the config below creates a redirect to http://localhost:3000// which leads to an error: Fetch error - Not Found http://localhost:3000//json.

{
    swagger: {
        info: { title: '' },
    },
    exposeRoute: true,
    routePrefix: '/',
}

[mcollina]

I'm currently swamped :/. It would be awesome to get a PR.