README: surround example with main() function
README: surround example with main() function

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