chore: fix JavaScript lint errors

PR-URL: #8293
Closes: #8282
Co-authored-by: Athan Reines <kgryte@gmail.com>
Reviewed-by: Athan Reines <kgryte@gmail.com>

Author: WillyEverGreen

lib/node_modules/@stdlib/fs/read-file/examples/index.js

@@ -18,22 +18,23 @@
 
 'use strict';
 
+var isError = require( '@stdlib/assert/is-error' );
 var readFile = require( './../lib' );
 
 /* Sync */
 
 var file = readFile.sync( __filename, 'utf8' );
 // returns <string>
 
-console.log( file instanceof Error );
+console.log( isError( file ) );
 // => false
 
 file = readFile.sync( 'beepboop', {
 	'encoding': 'utf8'
 });
 // returns <Error>
 
-console.log( file instanceof Error );
+console.log( isError( file ) );
 // => true
 
 /* Async */