Make filename relative

Author: benmccann

index.js

@@ -240,10 +240,11 @@ module.exports = function svelte(options = {}) {
 					}
 					: {};
 
+				const filename = path.relative(process.cwd(), id);
 				const compiled = compile(
 					code,
 					Object.assign(base_options, fixed_options, {
-						filename: id
+						filename
 					}, major_version >= 3 ? null : {
 						name: capitalize(sanitize(id))
 					})