Add switch statement spaces for consistency

Editor assessment

The subject says spacing around switch statements was added for consistency, which is clear and states its own motivation in the word consistency; a reader needs no diff. The fix type and curriculum scope are accurate for a code-style correction in challenge content. No body appears, which is justifiable for a small formatting change whose subject is self-sufficient. The Co-authored-by trailer crediting the reviewer is well formed and meaningful, the only footer present. Style is clean: imperative mood, no trailing period, comfortable length, consistent language. A small change communicated exactly as a small change should be, with nothing missing.