feat: create script to update Dockerfile

Author: rjhenry

Diff for: scripts/update_dockerfile.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+BOOKSTACK_VERSION=$(curl -L \
+  -H "Accept: application/vnd.github+json" \
+  -H "X-GitHub-Api-Version: 2022-11-28" \
+  https://api.github.com/repos/BookstackApp/Bookstack/releases/latest | \
+  jq -r .tag_name
+)
+
+echo "Latest: ${BOOKSTACK_VERSION}. Updating.."
+
+sed \
+  -i '' \
+  -e "s/^ENV BOOKSTACK_VERSION=.*/ENV BOOKSTACK_VERSION=${BOOKSTACK_VERSION}/" \
+  Dockerfile