Sylvia/docs/sfd

@mhoeber @lamagnifica SFD_ORA.rst and SFD_mathformatting.rst are ready for a dev review when you guys have the time. (SFD_certificates is still in the writing phase, so ignore that one for now.) Thanks!
is it a best practice to compose using another tool, or something that it would make sense to suggest? 
this section assumes that a text response has been requested -- perhaps state that explicitly?
(and is there any advice for other types of responses?)