Merge pull request #1720 from infosiftr/per-arch-note

Add an additional clarifying note to the top of the per-architecture repositories

update.sh

@@ -125,6 +125,12 @@ for image in "${images[@]}"; do
 		{
 			cat "$helperDir/autogenerated-warning.md"
 			echo
+
+			if [ -n "$ARCH_SPECIFIC_DOCS" ]; then
+				echo '**Note:** this is the "per-architecture" repository for the `'"$BASHBREW_ARCH"'` builds of [the `'"$repo"'` official image](https://hub.docker.com/_/'"$repo"') -- for more information, see ["Architectures other than amd64?" in the official images documentation](https://github.com/docker-library/official-images#architectures-other-than-amd64) and ["An image'\''s source changed in Git, now what?" in the official images FAQ](https://github.com/docker-library/faq#an-images-source-changed-in-git-now-what).'
+				echo
+			fi
+
 			echo -n "$deprecated"
 			cat "$helperDir/template.md"
 		} > "$targetFile"