This is the start of a reworking of our docs around the secrets API. There will be a number of follow-up patches before this document will be considered complete. Until this document is considered complete, I'm not adding this page to the table of contents. Also, to limit individual CR size, I've tossed TODOs on the areas that will be worked on in future CRs. Change-Id: I8599628d51f4b5aae9ec1b8fd76f419d5b38bdcc