fix(create-svelte): add hint when scaffolding

[theetrain]

Relates to #9317

A number of folks on Discord have been asking how to toggle options in the new 'Select additional options' step when running npm create svelte@latest. This change aims to provide a hint for this lesser-known prompt experience.

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[Rich-Harris]

Maybe make it a little shorter, so that it's less likely to break onto two lines?

Suggested change

	message: 'Select additional options (use arrow keys to navigate and SPACE to toggle options)',
	message: 'Select additional options (use arrow keys/space bar)',

[theetrain]

Sounds good to me 👍