Is it possible to put `.all-contributorsrc` in subfolders?

**Is your feature request related to a problem? Please describe.**
Right now it seems the `.all-contributorsrc` file can only be placed in the root folder. I would like to put it in the `.github` folder, is it possible?

**Describe the solution you'd like**
Not sure, but I feel we can relax the restriction by including `.github` as a valid location.

**Describe alternatives you've considered**
N/A

**Additional context**
N/A