Add GoReleaser configuration, CI workflows, and contributing guidelines; update .gitignore and Makefile

.github/workflows/release.yml

@@ -0,0 +1,57 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - "v*"
+
+run-name: "Release ${{ github.ref_name }}"
+
+permissions:
+  contents: read
+
+jobs:
+  goreleaser:
+    permissions:
+      contents: write
+      id-token: write # Required for SLSA
+    runs-on: ubuntu-latest
+    outputs:
+      hashes: ${{ steps.hash.outputs.hashes }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          cache: true
+
+      - name: Run GoReleaser
+        uses: goreleaser/goreleaser-action@v6
+        with:
+          distribution: goreleaser
+          version: "~> v2"
+          args: release --clean
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Generate hashes for provenance
+        id: hash
+        run: |
+          cd dist
+          echo "hashes=$(sha256sum * | grep -v checksums.txt | base64 -w0)" >> "$GITHUB_OUTPUT"
+
+  provenance:
+    needs: [goreleaser]
+    permissions:
+      actions: read
+      id-token: write
+      contents: write
+    uses: slsa-framework/slsa-github-generator/.github/workflows/generator_generic_slsa3.yml@v2.0.0
+    with:
+      base64-subjects: "${{ needs.goreleaser.outputs.hashes }}"
+      upload-assets: true