loader: add comment explaining text format

Co-authored-by: pdeveltere <pdeveltere@users.noreply.github.com>

Author: efekrskl

lib/internal/modules/esm/get_format.js

@@ -236,6 +236,7 @@ function getFileProtocolModuleFormat(url, context = { __proto__: null }, ignoreE
   throw new ERR_UNKNOWN_FILE_EXTENSION(ext, filepath);
 }
 
+// If the caller explicitly requests text format via import attributes, honor it regardless of file extension.
 function isExperimentalTextImport(importAttributes) {
   return getOptionValue('--experimental-import-text') &&
     importAttributes?.type === 'text';