Document all array creation methods in one place

[dstansby]

There's some nice docs on array creation in the ndarray for numpy docs, but it would be nice if there was a separate section in the main documentation that listed and briefly described all the ndarray methods for creating new arrays, e.g. zeros, linsapce, logspace etc.

[bluss]

The intended flow is that you go to ArrayBase: https://docs.rs/ndarray/0.15.6/ndarray/struct.ArrayBase.html

Under Contents there's a link called Constructor Methods for Owned Arrays

and there all the constructors are basically listed one by one.