ci(deploy): add Gitea Actions workflow for site publishing

- Add publish workflow to deploy main branch via SFTP
- Configure workflow dispatch and push-to-main triggers
- Use repository variables and secrets for SSH credentials
- Update README logo markup for consistent sizing

Signed-off-by: Alexander Davis <alex@adcm.uk>

.gitea/workflows/publish.yaml

@@ -0,0 +1,32 @@
+name: Publish to Server
+run-name: ${{ gitea.actor }} is publishing your site using Gitea Actions 🚀
+
+on:
+  workflow_dispatch:
+  # Trigger the workflow on push
+  push:
+    branches: [main]
+
+# Authenticate to the the server via ssh
+# and run our deployment script (sftp upload)
+jobs:
+  deploy:
+    name: Deploy
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: SFTP upload
+        uses: Dylan700/sftp-upload-action@latest
+        with:
+          server: ${{ vars.SSH_HOST }}
+          username: ${{ vars.SSH_USERNAME }}
+          password: ${{ secrets.KEY_PASSWORD }}
+          port: 22
+          uploads: |
+            ${{ vars.GIT_FOLDER }} => ${{ vars.SSH_FOLDER }}
+          delete: 'false'
+          ignore: |
+            *.git
+            */**/*git*