chore(MADEWITHVRTK.md): add new games and update format
chore(MADEWITHVRTK.md): add new games and update format

The MADEWITHVRTK list has a few more games added to it and the format
has been changed to group the games into their specific vendor.
Fulby/VRTK,gpvigano/VRTK,thestonefox/VRTK,mattboy64/SteamVR_Unity_Toolkit,Innoactive/IA-unity-VR-toolkit-VRTK,thestonefox/SteamVR_Unity_Toolkit,virror/VRTK,TMaloteaux/SteamVR_Unity_Toolkit,red-horizon/VRTK,adamjweaver/VRTK,gpvigano/SteamVR_Unity_Toolkit,gomez-addams/SteamVR_Unity_Toolkit