[LUADNS] Fix example keyword arguments

[aaron-sierra]

[LUADNS] Fix example keyword arguments

Description

Correct the example keyword arguments to allow successful login.

Function	Original	Proposed
Username	user=	key=
Password	key=	secret=

Status

• done, ready for review

Checklist (tick everything that applies)

• [ ] Code linting (required, can be done after the PR checks)
• [x] Documentation
• [ ] Tests
• [ ] ICLA (required for bigger changes)