README / Unit Test

1. slightly reword README description
2. add unit test for dot notation nested fetch

test('nested view fetch' , () => {
  const legGrpView = view.getView('InstrmtLegGrp.NoLegs')
  expect(legGrpView).toBeTruthy()
  const legGrp: IInstrumentLeg[] = legGrpView.toObject()
  expect(legGrp).toBeTruthy()
  expect(Array.isArray(legGrp))
  expect(legGrp.length).toEqual(2)
})