Create uf2 upload release asset in cmake action

.github/workflows/cmake.yml

@@ -52,3 +52,26 @@ jobs:
       shell: bash
       run: |
         cmake --build . --config $BUILD_TYPE -j 2
+
+    - name: Create Release
+      id: create_release
+      uses: actions/create-release@v1
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      with:
+        tag_name: ${{ github.ref }}
+        release_name: Release ${{ github.ref }}
+        draft: 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: ${{runner.workspace}}/example/build/stepper_example.uf2
+        asset_name: stepper_example.uf2
+        asset_content_type: application/octet-stream
+