add UmBox upload workflow (wooooo)

Author: thacuber2a03

.github/workflows/umbox.yml

@@ -0,0 +1,17 @@
+name: UmBox upload
+
+on:
+  push:
+    branches: [ master ]
+
+  workflow_dispatch:
+
+jobs:
+  upload:
+    runs-on: ubuntu-22.04
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: marekmaskarinec/umbox@master
+        with:
+          secret: ${{ secrets.UMBOX }}