Fix for https://github.com/docker/docker.github.io/issues/1413

Signed-off-by: John Mulhausen <john@docker.com>

docs/reference/builder.md

@@ -2,6 +2,8 @@
 title: "Dockerfile reference"
 description: "Dockerfiles use a simple DSL which allows you to automate the steps you would normally manually take to create an image."
 keywords: "builder, docker, Dockerfile, automation, image creation"
+redirect_from:
+- /reference/builder/
 ---
 
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