Add product comments (#54)

src/types/product-types.ts

@@ -151,6 +151,7 @@ export interface ProductFields {
   printFileWidth?: number;
   printFileHeight?: number;
   printFileDpi?: number;
+  comments?: string;
   // Below exists for Canvas frame in DB but in shop limits.php is used
   // minHeight: number;
   // minWidth: number;