Specify alternate URL instead of app.url?

[bbeng89]

First of all, thank you for this great package! I am somewhat new to Swagger, so please correct me if there's a better way to do this.

My issue is that my API is at https://{domain}/api. Since this package just replaces the URL with the app URL, the /api/ base path gets stripped off. The only way I can see to make this work right now is to prefix all my paths in the swagger file with /api/ and that doesn't feel right.

I think it would be nice if in the swagger-ui.php config file I could define a different URL than app.url. Something like this:

'server_url' => config('app.url') . '/api'

The default fallback could just be config('app.url') as it is now.

I would be happy to take a stab at a PR, just thought I'd open this up for discussion before putting in the work. Thanks!