reafactoring readme

tools/cloud_functions/bq_table_snapshots/README.md

@@ -29,17 +29,8 @@ The **bq-snap-start-process** Cloud Scheduler Job will run monthly and trigger t
 ## bq_backup_fetch_tables_names
 The **bq_backup_fetch_tables_names** cloud function will fetch all the table names in source_dataset_name. It will then apply filters based on tables_to_include_list and tables_to_exclude_list to determine the tables in scope. Finally, it will submit one Pub/Sub message per table. 
 
-The Cloud Function uses the following environment variables to determine which BigQuery project to use for compute and which to use for storing your BigQuery snapshots:
-* `DATA_PROJECT_ID` id of project used for BQ storage 
-* `PUBSUB_PROJECT_ID` id of project with P/S topic
-* `TABLE_NAME_PUBSUB_TOPIC_ID` name of P/S topic where this code will publish to
-
 ## bq_backup_create_snapshots
 The **bq_backup_create_snapshots** Cloud Function will submit a BigQuery job to create a snapshot for each table in scope. This Cloud Function will suffix the snapshot name with the snapshot datetime to guarantee a unique name. It will also calculate and set the expiration time of the snapshot based on seconds_before_expiration. Finally, it will determine the snapshot time based on crontab_format. 
-The following environment variables must be set:
-* `BQ_DATA_PROJECT_ID` id of project used for BQ storage
-* `BQ_JOBS_PROJECT_ID` id of project used for BQ compute
-
 
 ### About the crontab_format field
 If DATASET_1 has 500 tables, 500 Pub/Sub messages are sent, and 500 Cloud Function invocations are performed. If the Cloud Function used the current time when it creates the snapshots then these 500 snapshots will represent different points in time. To avoid this the Cloud Function will create the snapshots for the table as they were when the Cloud Scheduler job (bq-snap-start-process) was triggered. To achieve this the Cloud Function will calculate the previous interval based on **crontab_format**.