Make a matrix from two matrices : semi_augment

### 2.42.22 Make a matrix from two matrices : `semi_augment`

`semi_augment` concat two matrices with the same number of columns.
Input :

`semi_augment([[3,4],[2,1],[0,1]],[[1,2],[4,5]])`

Output :

`[[3,4],[2,1],[0,1],[1,2],[4,5]]`

Input :

`semi_augment([[3,4,2]],[[1,2,4]])`

Output :

`[[3,4,2],[1,2,4]]`

Note the difference with `concat`.
Input :

`concat([[3,4,2]],[[1,2,4]]`

Output :

`[[3,4,2,1,2,4]]`

Indeed, when the two matrix A and B have the same dimension, `concat` makes a matrix with the same number of rows than A and B by gluing them side by side.
Input :

`concat([[3,4],[2,1],[0,1]],[[1,2],[4,5]]`

Output :

`[[3,4],[2,1],[0,1],[1,2],[4,5]]`

but :

`concat([[3,4],[2,1]],[[1,2],[4,5]]`

Output :

`[[3,4,1,2],[2,1,4,5]]`