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CONTRIBUTING.md

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+# Contributing Guide
+
+## Where to start?
+
+Please check out the [issues tab](https://github.com/alxmrs/qarray/issues).
+Let's have a discussion over there before proceeding with any changes. Great
+minds think alike -- someone may have already created an issue related to your
+inquiry. If there's a bug, please let us know.
+
+If you're totally new to open source development, I recommend
+reading [Xarray's contributing guide](https://docs.xarray.dev/en/stable/contributing.html)
+.
+
+## Developer setup
+
+0. (Recommended) Create a project-specific python
+   environment. [(mini)Conda](https://docs.anaconda.com/free/miniconda/index.html)
+   or [Mamba](https://mamba.readthedocs.io/en/latest/)
+   is preferred.
+1. Clone the repository (bonus: [via SSH](https://docs.github.com/en/authentication/connecting-to-github-with-ssh/adding-a-new-ssh-key-to-your-github-account))
+   and `cd qarray` (the project root).
+1. Install dev dependencies via: `pip install -e ".[dev]`