Include API to Octave Package Manager

[isfmiho]

Using Octave's addpath function isn't ideal since there's no guarantee that different users will install the API in the same path. It would possibly make things easier if the API was on the Octave package manager.

https://github.com/gnu-octave/packages/blob/main/CONTRIBUTING.md

[petibub]

test