add: main release workflow

.github/workflows/main.yml

@@ -0,0 +1,43 @@
+name: main
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  release:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v22
+        with:
+          github_access_token: ${{ secrets.GITHUB_TOKEN }}
+      - run: nix profile install nixpkgs#gh
+      - run: |
+          echo "${ secrets.GITHUB_TOKEN }" | gh auth login --with-token
+      
+      - name: Get current version
+        id: version
+        run: echo "version=$(cat ./VERSION)" >> $GITHUB_OUTPUT
+
+      - run: nix build
+
+      - name: Create Release
+        uses: actions/create-release@v1
+        id: create_release
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ steps.version.outputs.version }}
+          draft: false
+          prerelease: false
+
+      - name: Upload Release Asset
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }}
+          asset_path: ./result/std.html.wasm
+          asset_name: std.html.wasm
+          asset_content_type: application/wasm