Add README to pong sample
Add README to pong sample

fable-compiler/Fable,inosik/Fable,ncave/Fable,inosik/Fable,fable-compiler/Fable,ncave/Fable,ncave/Fable,ncave/Fable,fable-compiler/Fable,fable-compiler/Fable,fable-compiler/Fable,ncave/Fable,fable-compiler/Fable,fable-compiler/Fable,ncave/Fable,ncave/Fable