Option to provide multiple files on the Web

Would it be possible to implement loading of multiple files? That way shellcheck can follow files sourced in scripts.

For example with this script
```bash
#! /bin/bash

# Import config file
. script.conf

# ... snip ...
```
I get the following output
```
Line 4:
. script.conf
  ^-- SC1091: Not following: script.conf was not specified as input (see shellcheck -x).
```