Add more docs to item and basic_service class
Add more docs to item and basic_service class

m-Schlitzer/ews-cpp,m-Schlitzer/ews-cpp,otris/ews-cpp,otris/ews-cpp,bkircher/ews-cpp,m-Schlitzer/ews-cpp,bkircher/ews-cpp,bkircher/ews-cpp,otris/ews-cpp,otris/ews-cpp