WECHSEL Tutorial Notebook

[AnesBenmerzoug]

This PR closes #1

It adds a tutorial notebook for WECHSEL, fixes issues and improves the package overall

Changes

• Track data artifacts from original methods' code to git lfs in order to use them for testing.
• Added notebook dependencies to dev dependency group.
• Fix bilingual dictionary alignement implementation.
• Get path to cache directory from platformdirs instead of Path.home() in order to respect user configuration through XDG_CACHE_DIR environment variable.
• Fix downloading of fasttext embeddings.
• Compute embeddings vectors in batches for weighted average initialization.
• Compute cosine similarity using scikit-learn instead of fastdist.
• Set smaller values in TopKWeights to -np.inf instead of 0.
• Added test for bilingual dictionary alignment.
• Created notebook demonstrating use of WECHSEL.
• Updated readme.