added inline README

1. In Silverpop: Create a query containing only the people who've participated in, say, TSW (e.g. "WHERE 'TSW' is not NULL").
2. In Silverpop: Export the query, with only the field "email".
3. In (a php script I'm writing now): CSV export file from Silverpop is split every 20,000 lines, with ",Y,P" added to the end of each line too.
4. In Engaging Networks: A campaign is created - in the case of TSW for the Brazil account it will be called "pt.forests.tigers.signup.manifesto".
5. In Engaging Networks: The CSV files created in step 3 are imported using the Supporter data > Import Supporters wizard. The first time it is done we create a saved format like "Tiger Shop Window Manifesto (Silverpop)", then we use that format to speed up the other file imports too. Each time we're just mapping email=email, Y=email_ok and P=pt.forests.tigers.signup.manifesto.