Parse hidden files

[loicreynier]

I am not sure if this is intended or not, but hidden files are not formatted while running treefmt in the project root directory. I do not see why hidden files, which are generally configuration files should not be formatted.

Describe the solution you'd like

I would like to have hidden files formatted while running treefmt in the project root directory.

Describe alternatives you've considered

Currently hidden files can be formatted by passing them as command line arguments as in

treefmt .pre-commit-config.yaml