Mighty is out!

Our first official release which marks Mighty's base version being finished.
Important features:

• DQN, PPO and SAC working and performing well on base gymnasium envs
• Pufferlib integration
• Integration with the basic features of CARL and DACBench
• a few examples for updates, buffers, exploration, meta components and runners

This is still work in progress, particularly the closer integration with contextual RL environments, but the core functionality is contained in this release already.