add a Taskfile

Taskfile.yml

@@ -0,0 +1,15 @@
+version: '3'
+env:
+  IMAGE: jswank/alpine-cli
+  NAME: alpine-cli
+  TAG: 3
+tasks:
+  default:
+    cmds:
+      - task: build
+  build:
+    desc: build a new image
+    cmds:
+      - (podman manifest exists {{.IMAGE}}:{{.TAG}} && podman manifest rm {{.IMAGE}}:{{.TAG}}) || true
+      - podman manifest create {{.IMAGE}}:{{.TAG}}
+      - podman build --platform linux/amd64,linux/arm64 --manifest {{.IMAGE}}:{{.TAG}} {{.CLI_ARGS}} -f Dockerfile ctx