feat: support deep base URLs

docker-entrypoint.jetty.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+# cspell:words mkdir
+# cspell:enableCompoundWords
+###########################################################
+
+# ensure context path starts with a slash
+export CONTEXT_PATH="/${BASE_URL#'/'}"
+
+# base image entrypoint
+if [ -x /docker-entrypoint.sh ]; then
+    /docker-entrypoint.sh "$@"
+else
+    exec "$@"
+fi