bug: deno deploy from URL fails

Good morning fellow Denozins! This is an issue I've been running into for quite a while now, sorry for not reporting it earlier.

I'm unable to deploy from a URL (or remote git repository) to Deno Deploy. This happens for me on **any** project that consists of anything more than one file. Importing from `deps.ts`? or a `src` or `lib` folder? Not gonna happen. This is the same regardless of whether I use the `?url=` parameter on the /new page, or if I select a git repository from my own account / orgs in the drop down (unless, as stated, it's only a main.tsx file I'm trying to deploy).

For example, on the [docland](https://doc.deno.land) landing page, theres a link that indicates a user can "deploy their own" version of it by simply clicking that link. Sweet, sounds like a plan. **_Except it never succeeds._**

I made a quick video to demonstrate the unexpected behavior (see below). I'm no expert on the matter but it seems like an issue with import maps or resolving relative imports within the source project.

> My two cents on the impact: This could present itself to be a major roadblock for onboarding new users, as many users will simply move on to something else when encountering something like this.

https://user-images.githubusercontent.com/11234104/185675285-b32de1ab-26b2-4f2e-8268-d7f726793864.mov

Reproduce the failure from the /new page using the ?url= parameter and a remote git repository, comparing a single main.tsx file with the multi-file docland project. Trace how remote projects and relative imports or import maps are resolved; done means multi-file projects with deps.ts and src or lib imports deploy successfully.

Written by the indexing model from the issue text.