Update developer's guide (#354)

Update developer's guide

---------

Co-authored-by: Dilan Pathirana <[email protected]>

Author: dweindl

doc/development.rst

@@ -24,3 +24,67 @@ Python compatibility
 --------------------
 
 We follow `numpy's Python support policy <https://numpy.org/neps/nep-0029-deprecation_policy.html>`_.
+
+Release process
+---------------
+
+1. Update the version number in ``petab/version.py``.
+
+2. Update the changelog in ``doc/CHANGELOG.md``.
+   The update content can be generated automatically:
+   draft a new dummy GitHub release with a dummy tag and the ``develop``
+   branch, then click :guilabel:`Generate release notes`.
+
+3. Create a pull request with the to-be-released changes to the main branch
+   (usually from ``develop``).
+
+4. Once the pull request is merged, create a new release on GitHub.
+   Make sure to set the tag to the version number prefixed with 'v'
+   (e.g., ``v1.0.0``), and the release title to ``libpetab-python $RELEASE_TAG``
+   (e.g., ``libpetab-python v1.0.0``).
+
+5. Check that the release is now available on PyPI.
+   The upload to PyPI is performed automatically by a GitHub Actions workflow,
+   which may take a few minutes to complete.
+
+6. Merge the main branch back into the `develop` branch.
+
+Style guide
+-----------
+
+Code style
+~~~~~~~~~~
+
+We use pre-commit with ruff to enforce code style. To install pre-commit and
+the pre-commit hooks, run:
+
+.. code-block:: bash
+
+    pip install pre-commit
+    pre-commit install
+
+To run the pre-commit checks manually on all, not just the modified files, run:
+
+.. code-block:: bash
+
+    pre-commit run --all-files
+
+Documentation style
+~~~~~~~~~~~~~~~~~~~
+
+We use `Sphinx <https://www.sphinx-doc.org/>`_ to generate the documentation.
+The documentation is written in `reStructuredText <https://www.sphinx-doc.org/en/master/usage/restructuredtext/index.html>`_.
+
+We use the `sphinx docstring-style <https://sphinx-rtd-tutorial.readthedocs.io/en/latest/docstrings.html>`__ for new code.
+The ``:param [ParamName]:`` and ``:return:`` statements are important when
+applicable.
+Manual type annotations (``:type  [ParamName]:``) are redundant and should be
+avoided.
+
+To build the documentation, run:
+
+.. code-block:: bash
+
+    cd doc
+    make html
+    # then open `build/html/index.html` in a browser