User data: post3PIDs

[chrisabruce]

Adds contact information to the user's account.

Adds contact information to the user's account.

This endpoint is deprecated in favour of the more specific /3pid/add and /3pid/bind endpoints.

.. Note:: Previously this endpoint supported a bind parameter. This parameter has been removed, making this endpoint behave as though it was false. This results in this endpoint being an equivalent to /3pid/bind rather than dual-purpose.