Data backend for dfint installer.

• metadata/hook.json contains info about releases of df-steam-hook-rs, configs, offset files
• metadata/hook_v2.json metadata for installer 0.2.0 and higher, also contains info about dfhooks library
• metadata/dict.json contains info about localization languages: url of their csv files, font files, encoding specific configs
• store directory contains files referenced from metadata, like encoding specific configs, offsets for different DF versions, and other misc. stuff.