ES-config: Add some information

Emulationstation shows the following information:
[DGen]
Old Genesis/Megadrive emulator

[RetroArch]
GB,GBC,NES,SNES,MASTERSYSTEM,GENESIS/MEGADRIVE,PSX

[GnGeo]
Old NeoGeo emulator
GNGEO 0.7
Merge pull request #281 from gizmo98/patch-3

ES-config: Add some information