Adding updates to the post-sales processes for sales@ and renewals@

@jjcordz Would you please review the new business inquiries and point to section on marketing handbook on lead routing? I'm not sure that the latest is.

@kyla @mollybeth @Cbrady would you please review the types of inquiries we receive for Sales@ and add anything that is missing? Also, can you add the explanation on how to add student users to an existing license key?

@csotomango @wilsonlau would you please review the inquiries forwarded directly to AR or existing SMB inquiries?

@ChadMalchow FYI- can we merge this now and iterate as changes are made by the team?