ci: add build and release workflow

- Create GitHub Actions workflow for building and releasing PDF
- Configure workflow to run on push and manual dispatch
- Set up Typst and compile main.typ to main.pdf
- Upload PDF as artifact
- Create GitHub release with PDF when a tag is pushed

Author: ShenMian

.github/workflows/build.yml

@@ -0,0 +1,32 @@
+name: Build
+
+on: [push, workflow_dispatch]
+
+permissions:
+  contents: write
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Typst
+        uses: typst-community/setup-typst@v4
+        
+      - name: Build
+        run: typst compile --font-path ${{ github.workspace }}/fonts main.typ main.pdf
+
+      - name: Upload PDF file
+        uses: actions/upload-artifact@v4
+        with:
+          name: Rendered
+          path: main.pdf
+
+      - name: Release
+        uses: softprops/action-gh-release@v2
+        if: github.ref_type == 'tag'
+        with:
+          name: "${{ github.ref_name }}"
+          files: main.pdf