This helper function generates a transition matrix at random for testing purposes
Examples
mat_T <- generate_random_T(3)
mat_T
#> [,1] [,2] [,3]
#> [1,] 0.7817953 0.2182047 0.0000000
#> [2,] 0.4501779 0.3361174 0.2137047
#> [3,] 0.0000000 0.5749021 0.4250979
rowSums(mat_T)
#> [1] 1 1 1