Fixes Issue #471 with Publish

- Add sed to Dockerfile; this sed exists on publish script; breaks headings/nav in files without metadata
- Ensure sed runs over storage-driver/ subdir
- Add metadata to all the files (including specs) that don't have it; this ensures they display correctly on publish
- Implement the fix for the showing up in Github
- Update template with GITHUB IGNORES

Signed-off-by: Mary Anthony <mary@docker.com>

docs/configuration.md

@@ -1,6 +1,8 @@
+<!--GITHUB
 page_title: Configure a Registry
 page_description: Explains how to deploy a registry 
 page_keywords: registry, service, images, repository
+IGNORES-->
 
 
 # Registry Configuration Reference