build: add hello world workflox

.woodpecker/my-first-workflow.yaml

@@ -0,0 +1,15 @@
+when:
+  - event: push
+    branch: main
+
+steps:
+  - name: build
+    image: debian
+    commands:
+      - echo "This is the build step"
+      - echo "binary-data-123" > executable
+  - name: a-test-step
+    image: golang:1.16
+    commands:
+      - echo "Testing ..."
+      - ./executable