Add README with local setup instructions

README.md

@@ -0,0 +1,27 @@
+# Resensys Site Status
+
+## Run locally
+
+1. Open the project in your IDE and `cd` into the `site_status` folder.
+
+2. Set up a virtual environment:
+
+   ```powershell
+   python -m venv .venv
+   .\.venv\Scripts\Activate.ps1
+   ```
+
+3. Install dependencies:
+
+   ```powershell
+   pip install -r requirements.txt
+   pip install requests
+   ```
+
+   `requests` is used by `api.py` and is not listed in `requirements.txt`.
+
+4. Start the app:
+
+   ```powershell
+   python api.py
+   ```