docs: updated README.md with initial version

README.md

@@ -1,2 +1,39 @@
-# penrose-laundry-signage
-Laundry signage in Penrose.
+# Penrose Laundry Signage
+
+This repository creates signage diagrams (via [Penrose](https://penrose.cs.cmu.edu/)) for laundry bins.
+
+## Files
+
+- **`domain/laundyr-signs.domain`**: The Penrose _Domain_ file declares the `Category` type and our relevant predicates:
+  - `HasLabel`
+  - `HasFrequency`
+  - `AcceptedItem`
+  - `RejectedItem`
+- **`style/laundyr-signs.style`**: The Penrose _Style_ file specifying how to draw signage for each `Category`.
+- **`substance/`**: Five different _Substance_ files, one per laundry category:
+  - `cottons.substance`
+  - `synthetics.substance`
+  - `underpants.substance`
+  - `wool.substance`
+  - `caps.substance`
+
+## How it works
+
+- Upon every push to `main` that changes a `.domain`, `.style`, or `.substance` file:
+  1. GitHub Actions (see [`.github/workflows/compile-penrose.yml`](.github/workflows/compile-penrose.yml)) installs [roger](https://www.npmjs.com/package/@penrose/roger).
+  2. For each Substance file, it produces a PDF sign in the `output/` directory.
+  3. Then merges them all into one PDF, `laundyr-signs.pdf`.
+  4. Publishes a GitHub Release with `laundyr-signs.pdf` attached.
+
+Check the **Releases** tab for the generated PDF signage, or simply clone and run:
+
+```bash
+npm install -g @penrose/roger
+mkdir -p output
+# Example for cottons only:
+roger trio \
+  substance/cottons.substance \
+  style/laundyr-signs.style \
+  domain/laundyr-signs.domain \
+  --out "output/cottons.svg"
+```