Refactor docs

Author: prouast

CONTRIBUTING.md

@@ -0,0 +1,68 @@
+# Contributing to vitallens-python
+
+Thank you for your interest in contributing! This guide will help you set up your development environment and run the test suite.
+
+## Development setup
+
+We recommend using a virtual environment to manage dependencies.
+
+### Clone and install
+
+Clone the repository and install the package in **editable mode** with development dependencies.
+
+```bash
+# Clone the repo
+git clone https://github.com/Rouast-Labs/vitallens-python.git
+cd vitallens-python
+
+# Create a virtual environment
+python -m venv venv
+source venv/bin/activate
+
+# Install in editable mode
+# This allows you to modify source code and see changes immediately.
+pip install -e .
+
+# Install dev tools
+pip install flake8 pytest build
+```
+
+## Running tests
+
+The test suite requires a valid API Key to verify integration with the live API.
+
+1. **Set the Environment Variable:**
+
+You must set `VITALLENS_DEV_API_KEY` before running tests.
+
+```bash
+# Mac/Linux
+export VITALLENS_DEV_API_KEY="your_api_key_here"
+
+# Windows (PowerShell)
+$env:VITALLENS_DEV_API_KEY="your_api_key_here"
+```
+
+2. **Run Pytest:**
+
+```bash
+pytest
+```
+
+## Linting
+
+We use `flake8` to ensure code quality. Please check your code before submitting a PR.
+
+```bash
+flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+```
+
+## Building the package
+
+To build the distribution archives (source and wheel) for PyPI:
+
+```bash
+python -m build
+```
+
+The artifacts will be generated in the `dist/` directory.