fix(readme): update the paper to cite

[felixchalumeau]

Update the README to link to QDax paper.

[codecov-commenter]

Codecov Report

Attention: 84 lines in your changes are missing coverage. Please review.

Comparison is base (f366797) 92.31% compared to head (559d166) 92.28%.
Report is 9 commits behind head on main.

Files	Patch %	Lines
qdax/environments/humanoidtrap.py	18.30%	58 Missing ⚠️
qdax/baselines/pbt.py	76.47%	12 Missing ⚠️
qdax/baselines/sac_pbt.py	96.46%	4 Missing ⚠️
qdax/core/emitters/pbt_me_emitter.py	96.82%	4 Missing ⚠️
qdax/environments/exploration_wrappers.py	0.00%	3 Missing ⚠️
qdax/environments/__init__.py	60.00%	2 Missing ⚠️
tests/default_tasks_test/jumanji_envs_test.py	98.14%	1 Missing ⚠️

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Additional details and impacted files

@@            Coverage Diff             @@
##             main     #161      +/-   ##
==========================================
- Coverage   92.31%   92.28%   -0.04%     
==========================================
  Files         103      116      +13     
  Lines        5816     6763     +947     
==========================================
+ Hits         5369     6241     +872     
- Misses        447      522      +75     

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[Lookatator]

Hi @felixchalumeau ! Thanks for the PR, I will try to fix the docs build later today.

I guess it'll be time soon to merge develop into master and make a new release!