Function insert 

pub fn insert<T: Element, D: Dimension>(
    a: &Array<T, D>,
    index: usize,
    values: &Array<T, IxDyn>,
    axis: usize,
) -> FerrayResult<Array<T, IxDyn>>

Insert values along an axis before a given index.

index is the position before which to insert. values is a 1-D array of values to insert (its length determines how many slices are added).

Analogous to numpy.insert().

Errors

Returns FerrayError::AxisOutOfBounds if axis is out of bounds. Returns FerrayError::IndexOutOfBounds if index > axis_len.