Fix the schema of given example at README.md
Fix the schema of given example at README.md

mattroberts297/spark-xml,lokm01/spark-xml,databricks/spark-xml,lokm01/spark-xml,databricks/spark-xml,mattroberts297/spark-xml,HyukjinKwon/spark-xml,lokm01/spark-xml,HyukjinKwon/spark-xml,HyukjinKwon/spark-xml,mattroberts297/spark-xml