feat(docs): create docs website

.github/workflows/docs.yml

@@ -0,0 +1,67 @@
+name: Docs
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'docs/**'
+      - '.github/workflows/docs.yml'
+  pull_request:
+    paths:
+      - 'docs/**'
+      - '.github/workflows/docs.yml'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+# One deployment at a time; a newer push cancels an older in-flight build.
+concurrency:
+  group: docs-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    name: Build site
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+        with:
+          # Full history so Docusaurus can show "last updated" dates.
+          fetch-depth: 0
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: npm
+          cache-dependency-path: docs/package-lock.json
+
+      - name: Install dependencies
+        run: npm ci
+        working-directory: docs
+
+      # The build fails on broken internal links and anchors, so this also
+      # serves as the docs check on pull requests.
+      - name: Build
+        run: npm run build
+        working-directory: docs
+
+      - uses: actions/upload-pages-artifact@v3
+        if: github.event_name != 'pull_request'
+        with:
+          path: docs/build
+
+  deploy:
+    name: Deploy to GitHub Pages
+    if: github.event_name != 'pull_request'
+    needs: build
+    runs-on: ubuntu-latest
+    permissions:
+      pages: write
+      id-token: write
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - id: deployment
+        uses: actions/deploy-pages@v4

.gitignore

@@ -91,6 +91,8 @@ tags
 
 out
 node_modules
+.docusaurus
+build
 *.tsbuildinfo
 
 Argon_ICCAD_2026.pdf

README.md

@@ -12,6 +12,24 @@ general-purpose programming language. The main goal of Argon is to allow interop
 enable the creation of most practical parametric cells, and allow for performance optimizations such
 as caching and incremental compilation.
 
+## Documentation
+
+The documentation site is published at <https://ucb-substrate.github.io/argon/>.
+It is built with Docusaurus and lives in [`docs/`](docs). Its pages are
+under [`docs/content/`](docs/content), split into [guides](docs/content/guides/index.md), a
+[language reference](docs/content/language/overview.md), a
+[GUI manual](docs/content/gui/workspace.md), and a
+[tools reference](docs/content/tools/overview.md), each with its own sidebar.
+
+```bash
+cd docs
+npm install
+npm start
+```
+
+Run `npm run build` for a production build with strict internal-link and anchor checks.
+See [`docs/README.md`](docs/README.md) for the layout of the site.
+
 ## Installation
 
 To use Argon, you will need: