Rl4co

Major release: refactoring of models, trainer and pipelines, and more! 🚀

- Refactored the old `task` class into a base class (`RL4COLitModule`) that is the base for RL algorithms (such as REINFORCE and PPO), following the discussion in 67
- New base class for construction methods: now encoder, decoder, policy, and model can be based on common parent classes to make implementation much more modular
- Added native loading from the checkpoint, which used to be buggy
- Nice new logo (we like it, but we are obviously biased, so feel free to give us your opinion ;) )
- Added mPDP environment (and added some WIP for EquityTransformer)
- New `RL4COTrainer` that automatically includes training tricks for RL
- Added Codecov coverage
- Better testing: now we thoroughly test most of the library, including training (the Hydra part as well!)
- Documentation overhaul: add Sphinx plugins for modularized, automatic docs
- ... and more!

Better handling of notebooks, refactoring, plots and more!

Changelog of this release:
- Add notebook with checkpointing, logging, testing and more and relative bugfixes + feats 83
- Refactor env embeddings into `init`, `context` and `dynamic`
- OP plotting
- PCTSP plotting
- Quickfix Lightning problem: https://github.com/Lightning-AI/lightning/pull/18022
- Quickfix docs
- Misc

**Full Changelog**: https://github.com/kaist-silab/rl4co/compare/v0.0.5...v0.0.6

Changelog

- Fix SDVRP dynamic embedding 82
- Add missing environments in testing
- Update quickstart notebook to be more informative
- Remove rendering titles to avoid cluttering
- Other minor misc. updates

Documentation, environment refactoring, SPCTSP and more!

- Add initial documentation on ReadTheDocs 80
- Major refactoring of environments: new subclasses (`get_action_mask`, `check_solution_validity`) and more modular operations such as `get_tour_length`, move the base class and utils under `common/`
- New SPCTSP environment
- Fix SDVRP, refactor as subclass of CVRP
- Fix OP with major refactoring; typos eltociear
- Add Slack chat links
- Add [paper link](https://arxiv.org/abs/2306.17100) and citation
- Move dev status to Beta (it was production stable - we wish it was! Perhaps in the future... 🤞🏼)
- Misc bug fixes

Bug Fixes and more!

Changelog:
- Solve 71 (`pip install` from PyPI now works!)
- Fix TSP rendering
- Add `pre-commit-config` (we will make a contribution guide in the near future)
- Linting action with Black+Ruff combo - handled by default by the pre-commit
- Add working Colab notebook with full training and testing of AM
- Add badges
- Misc

NOTE: please do not use this version, as it only contains the `__init__.py` file