Release 0.2.0

[felixchalumeau]

Hi guys,

Time for us to move to version 0.2.0 :tada:

This release introduces:

• fix a irrelevant 0.25 factor in td3 loss
• fix a overflow issue in the replay buffer
• clear the doc section about GPU usage with QDax
• update jax, brax and flax versions
• add a set of benchmarking functions from the QD community and clean the way we define our tasks
• add a caveat section in the doc
• add a QDax logo
• scale the action space of pointmaze to match the action space of Brax tasks
• add delay update in the PG emitter (PGAME)
• fix reinitialisation of optimizer state in PG variations (PGAME)
• introduce a wrapper to use fixed and known initial states for the Brax tasks
• fix Brax version in colab
• add the algorithm ME-ES
• introduce a meta emitter to use multiple emitters in parallel, called MultiEmitter
• add the algorithm CMA-ME with all its possible variants through the introduction of all three CMA emitters (improvement, random direction, optimization)
• fix CMA ES optimizer
• fix issue in CMA-MEGA
• add the algorithm QDPG through the introduction of the Diversity PG emitter
• refactor PGAME to use the multi emitter class
• add template for pull requests
• add DistributedMAPElites, an example of how to distribute a QDax algorithm on multiple devices
• fix run-image stage in docker
• avoid multiple jits of same method in for loops in our notebooks examples
• add the extra_scores in the API of the repertoire addition in MAP-Elites