Fix options type for options.floatingUIOptions (#3011)

* Fix options type for `options.floatingUIOptions`

* Fix docs build

Due to the way pnpm installs modules and how typescript declarations resolving works, typescript couldn’t be sure what the return type is. We can either specify the return value or cast (less safe)

shepherd.js/src/step.ts

@@ -17,6 +17,7 @@ import {
 // @ts-expect-error TODO: we don't have Svelte .d.ts files until we generate the dist
 import ShepherdElement from './components/shepherd-element.svelte';
 import { type Tour } from './tour.ts';
+import type { ComputePositionConfig } from '@floating-ui/dom';
 
 export type StepText =
   | string
@@ -134,7 +135,7 @@ export interface StepOptions {
   /**
    * Extra [options to pass to FloatingUI]{@link https://floating-ui.com/docs/tutorial/}
    */
-  floatingUIOptions?: object;
+  floatingUIOptions?: ComputePositionConfig;
 
   /**
    * Should the element be scrolled to when this step is shown?

shepherd.js/src/utils/floating-ui.ts

@@ -63,7 +63,7 @@ export function setupTooltip(step: Step): ComputePositionConfig {
 export function mergeTooltipConfig(
   tourOptions: StepOptions,
   options: StepOptions
-) {
+): { floatingUIOptions: ComputePositionConfig } {
   return {
     floatingUIOptions: deepmerge(
       tourOptions.floatingUIOptions || {},