ci: add option to trigger examples workflow manually (#667)

Author: kangasta

.github/workflows/examples.yml

@@ -8,6 +8,7 @@ on:
       - "go.mod"
       - "go.sum"
       - "examples/**.md"
+  workflow_dispatch:
 
 concurrency:
   group: ${{ github.repository }}-${{ github.workflow }}