Update README.md: only provide short usage info
Update README.md: only provide short usage info

The entire Getting Started Guide should be on the wiki, or in a separate docs folder, I think. We should only provide the most relevant info in the README.

[ci skip]

serious6/ews-java-api,travisc5/ews-java-api,wwahmed/ews-java-api,pheenomenon/ews-java-api,RavnSystems/ews-java-api,RavnSystems/ews-java-api,Sealinune/ews-java-api,AFaust/ews-java-api,Sealinune/ews-java-api,OfficeDev/ews-java-api,7thsense/ews-java-api,casimirenslip/ews-java-api-ms,travisc5/ews-java-api,chianquan/ews-java-api,candrews/ews-java-api,kentongray/ews-java-api,cfraser/ews-java-api,SpanningCloudApps/ews-java-api,casimirenslip/ews-java-api-ms,wwahmed/ews-java-api,OfficeDev/ews-java-api,avromf/ews-java-api,serious6/ews-java-api,7thsense/ews-java-api,mattguo/ews-java-api,chianquan/ews-java-api,cfraser/ews-java-api,candrews/ews-java-api,piraengu/ITcode,KatharineYe/ews-java-api,pheenomenon/ews-java-api,SpanningCloudApps/ews-java-api,kentongray/ews-java-api,AFaust/ews-java-api,mattguo/ews-java-api,piraengu/ITcode,KatharineYe/ews-java-api,avromf/ews-java-api