small corrections after v1.0

[donotdespair]

Hey @adamwang15,

I'm looking at our package and we need to improve some things:

• [x] update @references in documentation for estimate.BSVARSIGN

• [ ] @adamwang15 I'm looking at the code below (this has been redirected to #48)

  spec$prior$estimate_hyper (mu = TRUE, delta = TRUE, lambda = TRUE, psi = TRUE）

  and I think we should make this possible by running

  spec$estimate_hyper (mu = TRUE, delta = TRUE, lambda = TRUE, psi = TRUE）

  or both should be possible 😸

• [x] Shall we update the example in specify_narrative() so that the current one:

  specify_narrative(start = 166, periods = 1, type = "S", sign = 1, shock = 1, var = 6)

  was used in context:

  narrative = specify_narrative(start = 166, periods = 1, type = "S", sign = 1, shock = 1, var = 6)
  specification  = specify_bsvarSIGN$new(monetary, sign_narrative = list(narrative))

• [ ] documentation for spec$estimate_hyper #48