Allow sub directory functions

I'm using node, but it seems like this is true for every language.

I would like to be able to make the project structure cleaner and easier to maintain:
Let's say I have two functions (a, b), we are forced into a specific file structure which means all the functions must be in the same root directory where I call the functions app.

Currently, when we work with azure functions, this is the file structure we get:

```
project -|
|-a (function.json. index.js)
|-b (function.json. index.js)
|-shared_code
|-package.json
|-bin
|... more stuff, some is generated by azure
```

called as `/api/a`

In order to make the structure cleaner and less confusing I would like something like:

```
project -|
|-api-|
|-a (function.json. index.js)
|-b (function.json. index.js)
|-shared_code
|-package.json
|-bin
|... more stuff, some are generated by Azure
```

called as `/api.a`

There seems to be no option to specify where "func" should look for the `function.json` files, it would be nice if it would have used a glob and deep search for these files, or if we could specify the functions root where these files exist.