Add description of shell_load_package to the README
Add description of shell_load_package to the README

aishwaryarajagopal/Vertica-Extension-Packages,aishwaryarajagopal/Vertica-Extension-Packages,aishwaryarajagopal/Vertica-Extension-Packages,aishwaryarajagopal/Vertica-Extension-Packages