大関　金城　秀喜　カシオ

Fixes issue #33 Flatpak apps support. The flatpak support added is very naive. Further research and pull requests should be directed towards expanding and improving it.

Related issue: https://github.com/flathub/dev.goats.xivlauncher/issues/26 SteamAPI_Init() fails because Flatpak XIVLauncher (`dev.goats.xivlauncher`) can't detect Flatpak Steam (`com.valvesoftware.Steam`). ```bash [empjustine@huixtocihuatl ~]$ flatpak run 'dev.goats.xivlauncher' [S_API] SteamAPI_Init(): SteamAPI_IsSteamRunning() did not locate a running instance of...