adjust headings in README

apps/README.md

@@ -1,5 +1,5 @@
 
-## Generate report from the public data set
+# Generate report from the public data set
 
     spark-submit --conf spark.hadoop.fs.s3a.aws.credentials.provider=org.apache.hadoop.fs.s3a.AnonymousAWSCredentialsProvider --packages org.apache.hadoop:hadoop-aws:3.2.0,com.amazonaws:aws-java-sdk-s3:1.12.180,com.amazonaws:aws-java-sdk-core:1.12.180 ny_tlc_report.py --input 's3a://nyc-tlc/trip data/yellow_tripdata_2021-07.csv'
 
@@ -10,7 +10,7 @@ Notes:
 * Only one file is used for reporting in this example `yellow_tripdata_2021-07.csv`
 * This example works with `spark-3.1.3-bin-hadoop3.2` and Python 3.9.7. Other versions may require different dependency versions or even complete different dependencies altogether.
 
-### Links
+## Links
 
 [0] TLC trip data set https://www1.nyc.gov/site/tlc/about/tlc-trip-record-data.page
 [1] AWS Java SDK https://github.com/aws/aws-sdk-java