Add Usage instructions to both scripts

Signed-off-by: Jonathan Dowland <[email protected]>

Author: jmtd

gendocs.py

@@ -3,6 +3,12 @@
 # read in all the module YAML files specified for an image, in order, to
 # produce a comprehensive list of configuration environment variables,
 # then write them out to something useful
+#
+# Usage:
+#   ./gendocs.py name-of-image > output-asciidoc-file
+#
+# This script reads target/image.yaml, which is produced by a cekit
+# build (including --dry-run)
 
 import yaml
 import sys

gendocs.sh

@@ -5,6 +5,8 @@ set -euo pipefail
 # wish to generate documentation for, by switching to the relevant git
 # branches and tags and enumerating the image descriptors.
 # It is expected that this script is invoked via GitHub Actions.
+#
+# Usage: ./gendocs.sh
 
 engine=${engine-podman}