Example: docker (not yet documented)

Signed-off-by: Solomon Hykes <sh.github.6811@hykes.org>

examples/docker/main.cue

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"dagger.io/dagger"
+	"dagger.io/docker"
+)
+
+// Container source code (must include a Dockerfile)
+source: dagger.#Artifact
+
+// Container image
+container: docker.#Build & {
+	"source": source
+}