NRL-1320 add read me and log schema generation code for visibility

Author: jackleary

terraform/account-wide-infrastructure/modules/glue/LogSchemaGeneration/LogSchemaGeneration.ipynb

@@ -0,0 +1,5 @@
+# Log Schema Generation
+
+The Glue script uses pyspark to process log data. Due to the structure of each json document inside of a log group differing, we need to account for this variance.
+
+The notebook provides a way to automatically generate a pyspark schema for a log group without manual intervention. Point it at the desired group, and hit run all, then copy and paste the output into either producer_schema.py or consumer_schema.py.