Fix typo in docs for named arguments

[phoenixeliot]

The order of arguments in the output was swapped compared to what's correct; that's all.

[phoenixeliot]

Sharing my sanity checking just in case it helps anyone else sanity check:
https://rescript-lang.org/try

let addCoordinates = (~x, ~y) => {
  j`${Belt.Int.toString(x)}, ${Belt.Int.toString(y)}`
}

Js.log(addCoordinates(~x=5, ~y=6))
Js.log(addCoordinates(~y=6, ~x=5))

produces

function addCoordinates(x, y) {
  return String(x) + ", " + String(y);
}

console.log(addCoordinates(5, 6));
console.log(addCoordinates(5, 6));

exports.addCoordinates = addCoordinates;

[bobzhang]

@phoenixeliot thanks!