Add canary deploy workflow

.github/workflows/canary.yml

@@ -0,0 +1,20 @@
+name: Deploy Canary to Workshop
+
+on:
+  push:
+    branches: [ master ]
+  workflow_dispatch:
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@master
+      - uses: wiremod/gmod-upload@master
+        with:
+          id: 3066780663
+          changelog: ${{ github.event.head_commit.message }}
+        env:
+          STEAM_USERNAME: ${{ secrets.WIRETEAM_WORKSHOP_USERNAME }}
+          STEAM_PASSWORD: ${{ secrets.WIRETEAM_WORKSHOP_PASSWORD }}