add Butane example

Butane/.woodpecker.yaml

@@ -0,0 +1,24 @@
+when:
+  branch: main
+  event: [ push, pull_request ]
+
+steps:
+  - name: build
+    image: quay.io/coreos/butane:release
+    commands:
+      - bash ./script.sh
+
+  - name: push
+    image: docker.io/alpine/git:latest
+    environment:
+      MAIL:
+        from_secret: mail
+      CODEBERG_TOKEN:
+        from_secret: codeberg_token
+    commands:
+      - git remote set-url origin https://$CODEBERG_TOKEN@codeberg.org/<YOUR_GIT_REPO>
+      - git config user.email $MAIL
+      - git config user.name "Woodpecker CI"
+      - git add .
+      - git commit -m "CI translate Butane to Ignition files [SKIP CI]"
+      - git push origin main

Butane/script.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+# loop through all butane files in the current directory
+for i in *.bu ; do
+  # extract filename without extension
+  name=${i%.bu}
+
+  # use butane to convert the YAML file into an Ignition configuration
+  butane -ps ${i} -o ${name}.ign
+
+  if [ $? -eq 0 ]; then
+    echo "Converted ${i} to ${name}.ign successfully"
+  else
+    echo "Error converting ${i}"
+  fi
+done