[Bug]: static site generator endpoint doesn't work

### Problem description

When setting up a new project it says:

```
Entrypoint
The “entrypoint” to your application is the file that Deno Deploy will execute to start your server. Specify the path to that file in the “Entrypoint” field.

If you are using a static site generator, you might use this file as your entrypoint:

https://deno.land/std@0.188.0/http/file_server.ts

This is a generic static file server that will serve static assets from the root directory.
```

... but it won't let you set `https://deno.land/std@0.188.0/http/file_server.ts` as the entrypoint ('no branches found'), only local files.

### Steps to reproduce

- try to create 'new project'
- enter `https://deno.land/std@0.188.0/http/file_server.ts` as the entrypoint
- doesn't let you

### Expected behavior

let's you, or the docs are changed

### Environment

n/a

### Possible solution

_No response_

### Additional context

_No response_