Please create an AppData file for Piano Booster

[hughsie]

Please consider writing and installing an AppData file with the application description and some screenshots, else Piano Booster looks really bad in the GNOME and KDE Software Centers. We'd love to showcase more applications, but without the extra data file we can't. See http://people.freedesktop.org/~hughsient/appdata/ for details; thanks!

Richard

[romul]

PR is welcome https://github.com/captnfab/PianoBooster