Don't store Trakt access token in config directory

[polarstoat]

Currently sindresorhus/conf is used to store the Trakt token, which by default creates a config file in the system default user config directory ($XDG_CONFIG_HOME or otherwise ~/.config).

Storing authentication credentials/tokens in a config directory like this is bad practice as outlined in mislav/hub#1912.

A better location would be using the system default user data directory ($XDG_DATA_HOME or otherwise ~/.local/share).