Remove outdated STYLEGUIDE point

[r100-stack]

Changes

Removed outdated point (#2244 (comment)) from the STYLEGUIDE:

iTwinUI/STYLEGUIDE.md

Lines 83 to 114 in cbd8aa1

	### Destruct props and set default values
	```jsx
	// Good
	export const Alert = (props: AlertProps) => {
	const {
	children,
	className,
	type = 'informational',
	clickableText,
	onClick,
	onClose,
	style,
	isSticky = false,
	} = props;
	...
	```
	```jsx
	// Bad
	export const Alert = ({
	children,
	className,
	type = 'informational',
	clickableText,
	onClick,
	onClose,
	style,
	isSticky = false,
	}: AlertProps) => {
	...
	```

Unrelated: Reused some prop types in SearchBox.tsx to prevent duplication.

Testing

Tests still passing.

Docs

N/A