Minor updates to the readme

Some ideas for libraries. Not official yet.

Author: gordonwatts

README.md

@@ -12,8 +12,11 @@
 Given you have a selection string, this library will manage submitting it to a ServiceX instance and retreiving the data locally for you.
 The selection string is often generated by another front-end library, for example:
 
-- lib1
-- lib2
+- func_adl.xAOD (for ATLAS xAOD's)
+- func_adl.XXX (for flat ntuples)
+- xxx for columns
+
+These libraries are just coming up now, so this list is just an outline.
 
 # Prerequisites