[w3c/gamepad] Fix Promise type (#78)

Also replaced `void` with `boolean` because [the prose says](https://w3c.github.io/gamepad/extensions.html#gamepadhapticactuator-interface):

>pulse() applies a value to the actuator for duration milliseconds. The value passed to pulse() is clamped to limits defined by the actuator type. The returned Promise will resolve true once the pulse has completed.
You can view, comment on, or merge this pull request online at:

  https://github.com/w3c/gamepad/pull/78

-- Commit Summary --

  * fix Promise type

-- File Changes --

    M extensions.html (2)

-- Patch Links --

https://github.com/w3c/gamepad/pull/78.patch
https://github.com/w3c/gamepad/pull/78.diff

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/w3c/gamepad/pull/78