Central config file

First of all, thank you for your work!

We want that all of our projects are formatted with the same configuration, but we do not want to copy the configuration to every project (if we change something, we would have to update all the config files).

I suggest adding a field to the settings page where a path to a config file can be specified.

If a path is chosen, then this file gets used. Otherwise, the current logic should be used.