Implement a Verkle Tree

## Describe a new Feature

Study and implement a verkle tree, just for fun

## Describe what you expect! (Example)

```py
from merkly.verk import VerkleTree
```

## Docs

[Kuszmaul.pdf](https://github.com/olivmath/merkly/files/13800093/Kuszmaul.pdf)
