Prepare for v0.3.1 tag

PiperOrigin-RevId: 743012607

Author: jcitrin

docs/tutorials.rst

@@ -7,7 +7,8 @@ https://github.com/google-deepmind/torax/tree/main/torax/tutorials.
 The tutorials are intended to be run in either a Jupyter or Colab notebook.
 
 It is necessary to build your own notebook kernel in the same environment
-where you installed Torax.
+where you installed TORAX. These tutorials are tested for TORAX v0.3.1 and are
+not guaranteed to work with later versions due to API changes.
 
 First install the necessary dependencies. Running from the torax root directory:
 

pyproject.toml

@@ -5,7 +5,7 @@ build-backend = "setuptools.build_meta"
 [project]
 name = "torax"
 description = "Differentiable 1D tokamak plasma transport simulator in JAX."
-version = "0.3.0.dev"
+version = "0.3.1"
 readme = "README.md"
 requires-python = ">=3.10"
 license = {file = "LICENSE"}