Python - Prepare for release 0.10.0

[n1t0]

Added

• [Add a visualization utility to render tokens and annotations in a notebook #508]: Add a Visualizer for notebooks to help understand how the tokenizers work
• [Trainer improvements #519]: Add a WordLevelTrainer used to train a WordLevel model
• [Python releases build & upload Conda packages #533]: Add support for conda builds
• [Split Pre-Tokenizer #542]: Add Split pre-tokenizer to easily split using a pattern
• [Ability to train from memory #544]: Ability to train from memory. This also improves the integration with datasets
• [Python - Add components getter/setters to BaseTokenizer #590]: Add getters/setters for components on BaseTokenizer
• [Add fuse_unk option to SentencePieceBPETokenizer #574]: Add fust_unk option to SentencePieceBPETokenizer

Changed

• [Automatically stubbing the pyi files while keeping inspecting ability #509]: Automatically stubbing the .pyi files
• [Trainer improvements #519]: Each Model can return its associated Trainer with get_trainer()
• [Python - Mutable components #530]: The various attributes on each component can be get/set (ie.
  tokenizer.model.dropout = 0.1)
• [Improve Python API Reference and help #538]: The API Reference has been improved and is now up-to-date.

Fixed

• [Trainer improvements #519]: During training, the Model is now trained in-place. This fixes several bugs that were
  forcing to reload the Model after a training.
• [Fix BaseTokenizer enable_truncation docstring #539]: Fix BaseTokenizer enable_truncation docstring