Add GitHub Workflow to draft release

.github/workflows/release.yml

@@ -0,0 +1,35 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - "v*.*.*"
+
+jobs:
+
+  release:
+    name: Build release binaries
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ ubuntu-latest, macos-latest ]
+    steps:
+      - name: Checkout the repository
+        uses: actions/checkout@master
+      - name: Set the version
+        run: echo "version=${GITHUB_REF/refs\/tags\//}" >> $GITHUB_ENV
+      - name: Set the platform
+        run: echo "platform=${RUNNER_OS,,}" >> $GITHUB_ENV
+      - name: Compile the project
+        run: make clean && make
+      - name: Build the artifact
+        run: make build/janet-${{ env.version }}-${{ env.platform }}-x64.tar.gz
+      - name: Draft the release
+        uses: softprops/action-gh-release@v1
+        with:
+          draft: true
+          files: |
+            build/*.gz
+            build/janet.h
+            build/c/janet.c
+            build/c/shell.c