Discover all files if specified definition file is actually a directory

[cryptaliagy]

Currently, each definition file passed to quilla must be done so explicitly. This is in part because it's easier to push the burden onto the user, and in part because this enables the user to be certain about the order of precedence for the definitions file.

It could however be a usecase that a single team maintains a set of mutually exclusive definition files, such as:

{
    "LoginPage": {
        "my_definition": "some_xpath"
    }
}

{
    "HomePage": {
        "my_definition": "some_xpath"
    }
}

In this case, there will never be a conflict since each file will deal with a specific subset. It would then be beneficial to be able to specify to Quilla a directory where all such files exist, allowing users to have them be discovered by Quilla instead of manually specified.

Another idea would be to allow these folders to exist in a way that each file is namespaced to guarantee the lack of conflicts.