fix(breaking): always return array

[kanadgupta]

🧰 Changes

I had DX concerns about the string[] | string setup in the .convert() method and talked offline with @erunion and agreed that it should always return a string[], so this PR makes that change. This is a breaking change.

🧬 QA & Testing

Is this everything? I saw this line below but I think it's unrelated so I left it, but let me know if I'm wrong about this.

httpsnippet/src/targets/index.ts

Line 41 in fc92e40

) => string;