Add Dockerfile and GitLab CI Pipeline

Change-Id: Iafef7b6388667cf2d45c79a4a0e5d0eea224afba
diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
new file mode 100755
index 0000000..81d9073
--- /dev/null
+++ b/docker-entrypoint.sh
@@ -0,0 +1,6 @@
+#!/bin/sh
+set -e
+
+# Execute tei2korapxml with all passed arguments
+# Use the installed version from /usr/local/bin
+exec /usr/local/bin/tei2korapxml "$@"