Add Kruskals algorithm to MinimumSpanningTree project

[HLWeil]

Kruskals algorithm is a marginally more complex, but also more potent alternative to Prim's algorithm for finding not only minimum spanning trees but also minimum spanning forests. It could be added to the existing project or used in the future as a new project with the same basics.

Additonal Ressources:
https://algorithms.discrete.ma.tum.de/graph-algorithms/mst-kruskal/index_en.html