Clarified CIDR notation
Clarified CIDR notation

Added verbiage explaining that CIDR notation is an option for advanced users when whitelisting a range of IPs.
jacobmovingfwd/docs,Aonepathan/docs,hardikjain29/docs,jacobmovingfwd/docs,Aonepathan/docs,jacobmovingfwd/docs,jacobmovingfwd/docs,hardikjain29/docs,Aonepathan/docs,katieporter/docs,ksigler7/docs,sendgrid/docs,sendgrid/docs,hardikjain29/docs,Aonepathan/docs,Zaftula/docs,hardikjain29/docs,Zaftula/docs,Aonepathan/docs,Whatthefoxsays/docs,katieporter/docs,Zaftula/docs,ksigler7/docs,jacobmovingfwd/docs,katieporter/docs,Whatthefoxsays/docs,hardikjain29/docs,katieporter/docs,katieporter/docs,ksigler7/docs,Whatthefoxsays/docs,Zaftula/docs,Zaftula/docs,sendgrid/docs