Allow for base url

[SwatDoge]

I'd love to ability to set a base url. If you have a url like:

example.com/api/*

It would be great if you could set the base url to be /api/

[mattreid1]

The current behaviour is the path is taken from the hostname and path, e.g. http://0.0.0.0:3000/api. You can handle routes like the following:

app.get("/api/get", (ctx) => {
  return ctx.sendText("Hello");
});

Is this roughly what you mean or do you want to just do this?

app.get("/get", (ctx) => {
  return ctx.sendText("Hello");
});

[SwatDoge]

I'd like the last thing, where by default "/get" would get prefixed by "/api/" if you choose so. This would mean you could just write "/boots" "/get" instead of "api/boots" and "api/get".

Simular concept to the html base tag: https://www.w3schools.com/TAGs/tag_base.asp