fix fallback

docs/components/popup.md

@@ -1140,8 +1140,7 @@ Scroll the container to see how the popup changes it's fallback placement to pre
 ```
 
 ```jsx react
-import { useState } from 'react';
-import { SlPopup, SlSwitch } from '@shoelace-style/shoelace/dist/react';
+import { SlPopup } from '@shoelace-style/shoelace/dist/react';
 
 const css = `
   .popup-flip-fallbacks .overflow {

src/components/popup/popup.ts

@@ -304,7 +304,7 @@ export default class SlPopup extends ShoelaceElement {
           boundary: this.flipBoundary,
           // @ts-expect-error - We're converting a string attribute to an array here
           fallbackPlacements: this.flipFallbackPlacements,
-          fallbackStrategy: this.flipFallbackStrategy,
+          fallbackStrategy: this.flipFallbackStrategy === 'best-fit' ? 'bestFit' : 'initialPlacement',
           padding: this.flipPadding
         })
       );