release: add a prompt about DEVELOPMENT.md (#349)

I'm not saying I forgot to check the checklist in DEVELOPMENT.md before
releasing today, but... uh, I'm not saying I _didn't_ forget, either.

Author: LawnGnome

release.sh

@@ -2,6 +2,16 @@
 
 set -euf -o pipefail
 
+read -p 'Have you read DEVELOPMENT.md? [y/N] ' -n 1 -r
+echo
+case "$REPLY" in
+    Y|y) ;;
+    *)
+        echo 'Please read the Releasing section of DEVELOPMENT.md before running this script.'
+        exit 1
+        ;;
+esac
+
 if ! echo "$VERSION" | grep -Eq '^[0-9]+\.[0-9]+\.[0-9]+$'; then
   echo "\$VERSION is not in MAJOR.MINOR.PATCH format"
   exit 1