lguest: document --rng in example Launcher
lguest: document --rng in example Launcher

Rusty Russell wrote:
> Ah, it will appear as /dev/hwrng.  It's a weirdness of Linux that our actual
> hardware number generators are not wired up to /dev/random...

Reflected this in the documentation, thanks :-)

Signed-off-by: Rusty Russell <df9728c9e5104131c08c7adb03af425394842596@rustcorp.com.au>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas