ci(docs): add GitHub Actions workflow for building and deploying docs

- Create new workflow for generating and deploying documentation

.github/workflows/docs.yml

@@ -0,0 +1,57 @@
+name: Docs
+
+on:
+  push:
+    branches: [main]
+
+env:
+  CARGO_TERM_COLOR: always
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/bin/
+            ~/.cargo/registry/index/
+            ~/.cargo/registry/cache/
+            ~/.cargo/git/db/
+            target/
+          key: cargo-${{ runner.os }}-${{ hashFiles('**/Cargo.lock') }}
+
+      - name: Build docs
+        run: cargo doc --no-deps
+
+      - name: Add redirect
+        run: echo '<meta http-equiv="refresh" content="0;url=soukoban/index.html">' > target/doc/index.html
+
+      - name: Upload pages artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: target/doc
+
+  deploy:
+    name: Deploy
+    runs-on: ubuntu-latest
+    needs: build
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4