Add dependencies for making docs

pyproject.toml

@@ -51,6 +51,7 @@ box2d = ["gymnasium[box2d]>=0.26.0"]
 mujoco-legacy = ["mujoco-py>=2.1,<2.2", "cython<3"]
 jax = ["jax>=0.4.0", "jaxlib>=0.4.0"]
 mushroom-rl = ["mushroom-rl"]
+docs = ['sphinx==7.1.2', 'sphinx-rtd-theme==1.3.0rc1', 'myst-parser']
 
 all = [
     # include all the optional dependencies

setup.py

@@ -15,6 +15,7 @@ extras = {
     'mujoco-legacy': ['mujoco-py >=2.1,<2.2', 'cython<3'],
     'jax': ["jax >=0.4.0", "jaxlib >=0.4.0"],
     'mushroom-rl': ['mushroom-rl'],
+    'docs': ['sphinx==7.1.2', 'sphinx-rtd-theme==1.3.0rc1', 'myst-parser']
 }
 
 # All dependencies