Bundle default config files with package

[alexdewar]

Is your feature request related to a problem? Please describe

Users who install Auto-CORPus from a wheel (e.g. via pip) won't have access to the default config files in the configs/ directly, but the ones in there seem generically useful, so it would be good to distribute them too.

Describe the solution you'd like

Currently users have to pass in the path to a config file (whether one of the defaults or a custom one) via a command line argument. One option would be to add a different flag which works exclusively with the built-in configs (e.g. you'd pass in -b nature_genetics instead of -c configs/config_nature_genetics.json. You'd also need to move the configs directory to be inside autocorpus/ so that it's included in the wheel.