refactor: create constant for swiss qr line breaks

src/components/SwissInvoice.tsx

@@ -55,6 +55,7 @@ const encodeSwissQrInvoice = (
 ) => {
   const VERSION = "0220"; // 2.20
   const CODING = 1; // utf-8
+  const LINE_BREAK = "\n";
   const END_INDICATOR = "EPD";
 
   const creditorType = invoiceData.creditor.type || "S";
@@ -115,7 +116,7 @@ const encodeSwissQrInvoice = (
     END_INDICATOR,
   ]
     .flat()
-    .join("\n");
+    .join(LINE_BREAK);
 
   return invoice;
 };