normal_id_glm signature missing

According to the documentation one of the signatures for normal_id_glm is:

real normal_id_glm_lpdf(vector y | row_vector x, real alpha, vector beta, real sigma)

But this signature is not available in 2.26:

library(cmdstanr)
#> This is cmdstanr version 0.1.3
#> - Online documentation and vignettes at mc-stan.org/cmdstanr
#> - CmdStan path set to: /home/andrew/.cmdstanr/cmdstan-2.26.0
#> - Use set_cmdstan_path() to change the path

mod = "data {
  int<lower=0> N;
  vector<lower=0, upper=200>[N] kid_score;
  row_vector<lower=0, upper=1>[N] mom_hs;
}
parameters {
  real alpha;
  vector[1] beta;
  real<lower=0> sigma;
}
model {
  sigma ~ cauchy(0, 2.5);
  target += normal_id_glm_lpdf(kid_score | mom_hs, alpha, beta, sigma);
}
"
mod = cmdstan_model(write_stan_file(mod))
#> Compiling Stan program...
#> 
#> Semantic error in '/tmp/RtmpmtAWHQ/model-1ec5266a7c73.stan', line 13, column 12 to column 70:
#>    -------------------------------------------------
#>     11:  model {
#>     12:    sigma ~ cauchy(0, 2.5);
#>     13:    target += normal_id_glm_lpdf(kid_score | mom_hs, alpha, beta, sigma);
#>                      ^
#>     14:  }
#>     15:
#>    -------------------------------------------------
#> 
#> Ill-typed arguments supplied to function 'normal_id_glm_lpdf'. Available signatures:
#> (real, matrix, real, vector, vector) => real
#> (real, matrix, vector, vector, vector) => real
#> (vector, row_vector, real, vector, vector) => real
#> (vector, row_vector, vector, vector, vector) => real
#> (vector, matrix, real, vector, real) => real
#> (vector, matrix, vector, vector, real) => real
#> Instead supplied arguments of incompatible type: vector, row_vector, real, vector, real.
#> 
#> make: *** [make/program:53: /tmp/RtmpmtAWHQ/model-1ec5266a7c73.hpp] Error 1
#> Error: An error occured during compilation! See the message above for more information.

^{Created on 2021-02-01 by the reprex package (v0.3.0)}

Start with the normal_id_glm documentation linked in the issue and compare its listed signatures with the CmdStan 2.26 behavior shown in the R/cmdstanr reproduction. Confirm whether the signature is missing from the documented API or unavailable in the implementation, then update the relevant documentation or record the discrepancy so the documented signatures match the supported behavior.