added upload release asset

.github/workflows/release.yml

@@ -64,9 +64,15 @@ jobs:
         with:
           tag_name: ${{ github.ref }}
           release_name: Release ${{ github.ref }}
-          body: |
-            Changes in this Release
-            - First Change
-            - Second Change
           draft: false
-          prerelease: false
+          prerelease: false
+      - name: Upload Release Asset
+        id: upload-release-asset 
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }} # This pulls from the CREATE RELEASE step above, referencing it's ID to get its outputs object, which include a `upload_url`. See this blog post for more info: https://jasonet.co/posts/new-features-of-github-actions/#passing-data-to-future-steps 
+          asset_path: ./build/darwin-build-darwin-amd64.tar.gz
+          asset_name: darwin-build-darwin-amd64.tar.gz
+          asset_content_type: application/gzip