kettle_etl_workflow.png has some incorrect references

[tomschenkjr]

I made a few errors on this one:

• The use of ~/ is inconsistent with the rest of the documentation. Need to be changed to open-data-etl-utility-kit
• The log analysis tools (e.g., A_DatasetLogs.sh) are shown under open-data-etl-utility-kit/ETL/Utilities instead of the ../Tools directory
• The connection between the diagram and the rest of the text is unclear to readers. Need to make the documentation clearer for each step.