Add the load of the races respository files.

The main idea here is add some convention to add new content data for races, items, character classes, backgrounds and etc.

I used a little bit of meta programming. XD
Got it, but are you trying to solve a problem for longer future or just for now? I think that this data will not be constants in memory, or will it?

If so, why not use YAML instead of loading ruby files? With YAML you can have the hash representation, so loading then from files would be more clear.

However, one issue is that now you are accessing all hash keys with `symbol` not string, so you will either have to use `symbolize_keys` are `with_indifferent_access`.