Update AUTHORS header to indicate it's generated

Using both @generated, and using Go's format for generated files,
to match the format we now use on moby/moby.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

AUTHORS

@@ -1,5 +1,6 @@
-# This file lists all individuals having contributed content to the repository.
-# For how it is generated, see `scripts/docs/generate-authors.sh`.
+# File @generated by scripts/docs/generate-authors.sh. DO NOT EDIT.
+# This file lists all contributors to the repository.
+# See scripts/docs/generate-authors.sh to make modifications.
 
 Aanand Prasad <aanand.prasad@gmail.com>
 Aaron L. Xu <liker.xu@foxmail.com>

scripts/docs/generate-authors.sh

@@ -5,8 +5,9 @@ set -e
 OUT="${1:-.}"
 {
 	cat <<-'EOH'
-	# This file lists all individuals having contributed content to the repository.
-	# For how it is generated, see `scripts/docs/generate-authors.sh`.
+	# File @generated by scripts/docs/generate-authors.sh. DO NOT EDIT.
+	# This file lists all contributors to the repository.
+	# See scripts/docs/generate-authors.sh to make modifications.
 	EOH
 	echo
 	git log --format='%aN <%aE>' | LC_ALL=C.UTF-8 sort -uf