Add note about what to apt-get on Ubuntu
Add note about what to apt-get on Ubuntu

googlestadia/renderdoc,TurtleRockStudios/renderdoc_public,etnlGD/renderdoc,adrianbu/renderdoc,etnlGD/renderdoc,Anteru/renderdoc,Lssikkes/renderdoc,googlestadia/renderdoc,Zorro666/renderdoc,Lssikkes/renderdoc,victor-moya/renderdoc,Anteru/renderdoc,etnlGD/renderdoc,TurtleRockStudios/renderdoc_public,Zorro666/renderdoc,Velro/renderdoc,Yours3lf/renderdoc,Zorro666/renderdoc,etnlGD/renderdoc,adrianbu/renderdoc,adrianbu/renderdoc,cgmb/renderdoc,Anteru/renderdoc,Anteru/renderdoc,etnlGD/renderdoc,Velro/renderdoc,adrianbu/renderdoc,Velro/renderdoc,victor-moya/renderdoc,michaelrgb/renderdoc,moradin/renderdoc,moradin/renderdoc,Velro/renderdoc,googlestadia/renderdoc,Zorro666/renderdoc,victor-moya/renderdoc,etnlGD/renderdoc,moradin/renderdoc,Anteru/renderdoc,googlestadia/renderdoc,victor-moya/renderdoc,Lssikkes/renderdoc,Yours3lf/renderdoc,moradin/renderdoc,baldurk/renderdoc,baldurk/renderdoc,cgmb/renderdoc,moradin/renderdoc,Velro/renderdoc,Yours3lf/renderdoc,cgmb/renderdoc,Anteru/renderdoc,michaelrgb/renderdoc,victor-moya/renderdoc,baldurk/renderdoc,michaelrgb/renderdoc,Anteru/renderdoc,Lssikkes/renderdoc,Velro/renderdoc,Yours3lf/renderdoc,Lssikkes/renderdoc,victor-moya/renderdoc,Lssikkes/renderdoc,Zorro666/renderdoc,googlestadia/renderdoc,adrianbu/renderdoc,michaelrgb/renderdoc,moradin/renderdoc,Yours3lf/renderdoc,baldurk/renderdoc,cgmb/renderdoc,googlestadia/renderdoc,TurtleRockStudios/renderdoc_public,TurtleRockStudios/renderdoc_public,cgmb/renderdoc,baldurk/renderdoc,baldurk/renderdoc,TurtleRockStudios/renderdoc_public,adrianbu/renderdoc,Yours3lf/renderdoc,TurtleRockStudios/renderdoc_public,Zorro666/renderdoc,michaelrgb/renderdoc