Add Minimum Spanning Tree in Haskell

[ricardomaps]

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Project name: Minimum Spanning Tree
Project link: https://sampleprograms.io/projects/minimum-spanning-tree
Language: Haskell

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Official Language Style Guide:
Official Language Website:
Official Language Docker Image: https://hub.docker.com/r/repository/image

The project link must be a link to a project on the Sample Programs Website project list.
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please first make a pull request to the Sample Programs Website.