chore: remove unused file

src/format.ts

@@ -1,24 +0,0 @@
-import { Mail, Options } from '../types.ts'
-import { Contact } from './contact.ts'
-
-export function format(
-	from: Contact,
-	to: Contact[],
-	subject: string,
-	body: string,
-	options: Partial<Options>,
-): Mail {
-	const defaultOptions: Options = {
-		from,
-		cc: [],
-		cci: [],
-		attachments: [],
-	}
-
-	return {
-		to,
-		subject,
-		body,
-		options: { ...defaultOptions, ...options },
-	}
-}