Validator Committee is defined in terms of state definition & mutation logic

[danlessa]

Src: https://hackmd.io/mgRskzOcTHycxwtcxn4nsA

eg.

Prior to the start of an epoch, let's say, at time :
300 validators are drawn (based on score) to the validator committee from the validator set (i.e. from the set of staked users)
The validator committee stays the same for all slots in an epoch