feat: add CD workflow

GitHub Actions workflow that SSHes into the server after tests pass.

Author: Pyker

.github/workflows/deploy.yml

@@ -0,0 +1,19 @@
+name: Deploy
+
+on:
+  workflow_run:
+    workflows: [Tests]
+    types: [completed]
+    branches: [master]
+
+jobs:
+  deploy:
+    if: github.event.workflow_run.conclusion == 'success'
+    runs-on: ubuntu-latest
+    steps:
+      - run: |
+          mkdir -p ~/.ssh
+          echo "${{ secrets.DEPLOY_SSH_KEY }}" > ~/.ssh/id_ed25519
+          chmod 600 ~/.ssh/id_ed25519
+          ssh-keyscan -H ${{ secrets.DEPLOY_HOST }} >> ~/.ssh/known_hosts
+          ssh ${{ secrets.DEPLOY_USER }}@${{ secrets.DEPLOY_HOST }}