Update Contributing.

CONTRIBUTING.md

@@ -1,9 +1,135 @@
-# CONTRIBUTING
+# CONTRIBUTING TO CONTINUITY
 
-## Pre-commit hook
+The goal of Continuity is to be a repository of architectures and benchmarks for
+operator learning with neural networks, and its applications.
 
-Make sure to install the pre-commit hook before committing:
+Contributions are welcome from anyone in the form of pull requests,
+bug reports and feature requests.
+
+## Local development
+
+This project uses [black](https://github.com/psf/black) to format code and
+[pre-commit](https://pre-commit.com/) to invoke it as a git pre-commit hook.
+
+Run the following to set up the pre-commit git hook to run before pushes:
 
 ```bash
-pre-commit install
+pre-commit install --hook-type pre-push
+```
+
+## Setting up your environment
+
+We strongly suggest using some form of virtual environment for working with the
+library. E.g. with venv:
+
+```shell
+python -m venv ./venv
+. venv/bin/activate
+pip install -r docs/requirements.txt
+```
+
+## Editable installation
+
+A very convenient way of working with your library during development is to
+install it in editable mode into your environment by running
+
+```shell
+pip install -e .
+```
+
+## Build documentation
+
+API documentation and examples from notebooks are built with
+[mkdocs](https://www.mkdocs.org/), with versioning handled by
+[mike](https://github.com/jimporter/mike).
+
+Notebooks are an integral part of the documentation as well.
+
+Use the following command to build the documentation the same way it is
+done in CI:
+
+```bash
+mkdocs build
+```
+
+Locally, you can use this command instead to continuously rebuild documentation
+on changes to the `docs` and `src` folder:
+
+```bash
+mkdocs serve
+```
+
+This will rebuild the documentation on changes to `.md` files inside `docs`,
+notebooks and python files.
+
+In order to build the documentation locally (which is done as part of the tox
+suite) [pandoc](https://pandoc.org/) is required. Except for OSX, it should be
+installed automatically as a dependency with `requirements-docs.txt`. Under OSX
+you can install pandoc (you'll need at least version 2.11) with:
+
+```shell
+brew install pandoc
+```
+
+## Testing
+
+Automated builds, tests, generation of documentation and publishing are handled
+by [CI pipelines](#CI). Before pushing your changes to the remote we recommend
+to execute `pytest` locally in order to detect mistakes early on and to avoid
+failing pipelines.
+
+## Notebooks
+
+We use notebooks both as documentation (copied over to `docs/examples`) and as
+integration tests. All notebooks in the `notebooks` directory are executed
+during the test run.
+
+Because we want documentation to include the full dataset, we commit notebooks
+with their outputs running with full datasets to the repo. The notebooks are
+then added by CI to the section
+[Examples](https://aai-institute.github.io/continuity/examples.html) of the
+documentation.
+
+### Hiding cells in notebooks
+
+You can isolate boilerplate code into separate cells which are then hidden
+in the documentation. In order to do this, cells are marked with tags understood
+by the mkdocs plugin
+[`mkdocs-jupyter`](https://github.com/danielfrg/mkdocs-jupyter#readme),
+namely adding the following to the metadata of the relevant cells:
+
+```yaml
+"tags": [
+  "hide"
+]
+```
+
+To hide the cell's input and output.
+
+Or:
+
+```yaml
+"tags": [
+  "hide-input"
+]
+```
+
+To only hide the input and
+
+```yaml
+"tags": [
+  "hide-output"
+]
+```
+for hiding the output only.
+
+### Plots in Notebooks
+If you add a plot to a notebook, which should also render nicely in browser
+dark mode, add the tag *invertible-output*, i.e.
+
+```yaml
+"tags": [
+  "invertible-output"
+]
 ```
+This applies a simple CSS-filter to the output image of the cell.

README.md

@@ -31,19 +31,24 @@ pip install -e .
 ```
 
 ## Usage
-Our [Documentation](https://aai-institute.github.io/continuity/) contains a verbose introduction to operator learning, a collection of examples using Continuity, and a class documentation.
+Our [Documentation](https://aai-institute.github.io/continuity/) contains a
+verbose introduction to operator learning, a collection of examples using
+Continuity, and a class documentation.
 
 In general, the operator syntax in Continuity is
 ```python
 v = operator(x, u(x), y)
 ```
 mapping a function `u` (evaluated at `x`) to function `v` (evaluated in `y`).
-For more details, see [Learning Operators](https://aai-institute.github.io/continuity/operators/index.html).
+For more details, see
+[Learning Operators](https://aai-institute.github.io/continuity/operators/index.html).
 
 ## Contributing
-If you find a bug or have a feature request, please open an issue on GitHub. If
-you want to contribute code, please fork the repository and submit a pull
-request.
+Contributions are welcome from anyone in the form of pull requests, bug reports
+and feature requests. If you find a bug or have a feature request, please open
+an issue on GitHub. If you want to contribute code, please fork the repository
+and submit a pull request. See [CONTRIBUTING.md](CONTRIBUTING.md) for details on
+local development.
 
 ## License
 This project is licensed under the GNU LGPLv3 License - see the