VS Code cannot find module in my Typescript project

My project is a Typescript project with a browser part and a server part. Because of that, I need to have two separate tsconfig.json in order to build the browser library and the server process using node. I am using Visual Studio Code.

The project

Here is the folder structure:

myproject
 |
 +-src
 |  |
 |  +-server
 |  |  |
 |  |  +-server.ts
 |  |  +-<several-ts-files>
 |  |  +-tsconfig.ts
 |  +-main.ts
 |  +-<several-ts-files>
 |  +-disposable.ts
 |  +-tsconfig.ts
 +-out

When building the server, I will go: tsc --project src\server, when building the client, I will go: tsc --project src.

The problem

In one of my files: src\main.ts, I have the following:

import disposable = require('./disposable.ts');

export module Browser {
  export class MyClass implements disposable.Disposable {
    // Stuff
  }
}

Since the browser side part uses AMD, I am specifying it in src/tsconfig.json: "module": "amd"! Visual Studio Code marks './disposable.ts' inside the require with a red line with error:

Cannot find module './disposable.ts'

Questions

1. Is this two tsconfig.json approach wrong?
2. Why can't Code find my modules?

Can it be...

I remember once somebody told me that Code needs a tsconfig.json file to understand how the developer wants to build the code. However when we have two and they are not in the root? Do all editors behave like that?