Format files using prettier

[FirelightFlagboy]

I've added pre-commit + prettier hook to format the files present on the repo.

The reason why I've formatted the files is because I've used a script to update the pokedex but I needed that the file to be formatted to simplify the git-diff.

Note: the reason only state that I need a formatted pokedex.json & a formatter, not which formatter or style I need, so if you have some preferences I can use those