Special file names as $path cause errors

[daimond113]

If a special file name, such as init.luau, init.client.luau, or init.server.luau (and any others as well, probably) is used as a $path's value the following error is thrown:

[ERROR rojo] Rojo project referred to a file using $path that could not be turned into a Roblox Instance by Rojo.
        Check that the file exists and is a file type known by Rojo.

It can be reproduced with a project file like this:

{
    "name": "a",
    "tree": {
        "$path": "init.luau"
    }
}

and is thrown despite the file existing. However, this does not happen if a non-special file name is used.