* Docs: Update description for create + update user
This change updates the documentation for the user creation API,
fixing errors mentioned in #1717:
- it's either `username` or `email` that is required on creation.
`name` is not required.
- `name` is the only required field when updating a user.
* docs: Fix overzealous prettier formatting
* docs: updated requirements for put: name OR email
Adds an explanation of what the various properties in the payload
object to the `user-admin` endpoint does. Most seem fairly
self-explanatory, but I'm not entirely sure what `sendEmail` does.
Requires validation by a third party before merging.
