Support checking multiple configuration files

[astorije]

I currently have 2 tslint.yml files: one at the root folder, and one in test/ that extends the root one. To be able to check both, it seems to me that I need to run:

tslint-config-prettier-check ./tslint.yml && tslint-config-prettier-check ./test/tslint.yml

It would be nice to be able to check both of those in a single command. In short, support of any of the following:

tslint-config-prettier-check .{,/test}/tslint.yml
tslint-config-prettier-check **/tslint.yml
# etc.