A bit more detail about where data gets stored

Don't store this on AWS kids!

README.md

@@ -5,3 +5,6 @@ Reads a config file in the same dir (ldapscanner.cfg)
 and then scans for changes since last time it was ran.
 
 Base your config on ldapscanner.cfg.dist
+
+Previous run data is stored in `.last.json`
+Current diff data is stored in `.current_diff.json`