add funtion support for confirmCancel

[taozhiyu]

demo

Promise function:

// TypeScript
{
  ...
  confirmCancel: () => {
    return new Promise<boolean>((resolve) => {
      // my dialog component
      dialog
        .open(
          "Are you sure you want to stop the tour?",
          "You can watch it again in setting paddle"
        )
        .then((res: boolean) => {
          resolve(res);
        });
    });
  },
  ...
}

https://github.com/shipshapecode/shepherd/blob/1076b0c37465cb48968b5f7159e08033cceaab20/test/unit/tour.spec.js#L295-L335
Unit tests have been passed.

[taozhiyu]

Can anyone help to see if there is really a problem with this pr?

It doesn't seem to pass the 'cognitive complexity' test, but I don't really know how to reduce it any more.

(In fact, I only added one judgement).

[taozhiyu]

Hi, is there anything else I need to do?

I see that this PR has not been merged, I just don't know if there is anything else that needs to be done.

[dvopalecky]

Hello, thank you for this feature. @RobbieTheWagner, when do you plan to release a new version in npm with this update? Thank you

[RobbieTheWagner]

A new version has been released