version 0.1.9

[AnFreTh]

This pull request introduces a new neural topic model, updates documentation, and makes several improvements to the codebase. The most important changes include adding the NSTM model, updating the README and documentation, and modifying the preprocessing steps.

New Model Addition

• Added the NSTM (Neural Topic Model via Optimal Transport) implementation in stream_topic/models/neural_base_models/nstm_base.py.
• Included NSTM in the __init__.py file for models. [1] [2]

Documentation Updates

• Updated the README.md to include a new GIF and remove outdated images. [1] [2]
• Added NSTM to the docs/api/models/models.rst file.
• Changed the kernel specification in Jupyter notebooks to use Python (stream_topic_venv). [1] [2]

Preprocessing and Configuration Changes

• Updated the default preprocessing steps to include configurations for NSTM in default_preprocessing_steps.json.
• Replaced the octis corpus with the brown corpus in the topic extraction module. [1] [2] [3] [4] [5]

Version and Dependency Updates

• Incremented the version number to 0.1.9 in __version__.py.
• Removed the octis dependency from docs/conf.py.

Other Code Changes

• Added the sinkhorn_loss function to stream_topic/utils/sinkhorn_loss.py.
• Changed the default expansion_corpus from octis to brown in the CEDC model. [1] [2]