post https://app.asana.com/api/1.0/portfolios
Creates a new portfolio in the given workspace with the supplied name.
Note that portfolios created in the Asana UI may have some state
(like the “Priority” custom field) which is automatically added
to the portfolio when it is created. Portfolios created via our
API will not be created with the same initial state to allow
integrations to create their own starting state on a portfolio.