Add outputs.files task to plan

Signed-off-by: Helder Correia <174525+helderco@users.noreply.github.com>

tests/plan/outputs/directories/outputs.cue

@@ -0,0 +1,17 @@
+package main
+
+import "dagger.io/dagger/engine"
+
+engine.#Plan & {
+	actions: data: engine.#WriteFile & {
+		input:       engine.#Scratch
+		path:        "/test"
+		permissions: 0o600
+		contents:    "foobar"
+	}
+
+	outputs: directories: test: {
+		contents: actions.data.output
+		dest:     "./out"
+	}
+}