doc: update code examples for node:url module

There are many things called `url` in this page including `url` module,
`URL` instances, etc.

The original example was not clear where these methods come from.

PR-URL: nodejs#38645
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/url.md

@@ -959,18 +959,37 @@ added: v10.12.0
 This function ensures the correct decodings of percent-encoded characters as
 well as ensuring a cross-platform valid absolute path string.
 
-```js
-new URL('file:///C:/path/').pathname;    // Incorrect: /C:/path/
-fileURLToPath('file:///C:/path/');       // Correct:   C:\path\ (Windows)
+```mjs
+import { fileURLToPath } from 'url';
+
+const __filename = fileURLToPath(import.meta.url);
+
+new URL('file:///C:/path/').pathname;      // Incorrect: /C:/path/
+fileURLToPath('file:///C:/path/');         // Correct:   C:\path\ (Windows)
+
+new URL('file://nas/foo.txt').pathname;    // Incorrect: /foo.txt
+fileURLToPath('file://nas/foo.txt');       // Correct:   \\nas\foo.txt (Windows)
+
+new URL('file:///你好.txt').pathname;      // Incorrect: /%E4%BD%A0%E5%A5%BD.txt
+fileURLToPath('file:///你好.txt');         // Correct:   /你好.txt (POSIX)
+
+new URL('file:///hello world').pathname;   // Incorrect: /hello%20world
+fileURLToPath('file:///hello world');      // Correct:   /hello world (POSIX)
+```
 
-new URL('file://nas/foo.txt').pathname;  // Incorrect: /foo.txt
-fileURLToPath('file://nas/foo.txt');     // Correct:   \\nas\foo.txt (Windows)
+```cjs
+const { fileURLToPath } = require('url');
+new URL('file:///C:/path/').pathname;      // Incorrect: /C:/path/
+fileURLToPath('file:///C:/path/');         // Correct:   C:\path\ (Windows)
 
-new URL('file:///你好.txt').pathname;    // Incorrect: /%E4%BD%A0%E5%A5%BD.txt
-fileURLToPath('file:///你好.txt');       // Correct:   /你好.txt (POSIX)
+new URL('file://nas/foo.txt').pathname;    // Incorrect: /foo.txt
+fileURLToPath('file://nas/foo.txt');       // Correct:   \\nas\foo.txt (Windows)
 
-new URL('file:///hello world').pathname; // Incorrect: /hello%20world
-fileURLToPath('file:///hello world');    // Correct:   /hello world (POSIX)
+new URL('file:///你好.txt').pathname;      // Incorrect: /%E4%BD%A0%E5%A5%BD.txt
+fileURLToPath('file:///你好.txt');         // Correct:   /你好.txt (POSIX)
+
+new URL('file:///hello world').pathname;   // Incorrect: /hello%20world
+fileURLToPath('file:///hello world');      // Correct:   /hello world (POSIX)
 ```
 
 ### `url.format(URL[, options])`
@@ -999,7 +1018,22 @@ string serializations of the URL. These are not, however, customizable in
 any way. The `url.format(URL[, options])` method allows for basic customization
 of the output.
 
-```js
+```mjs
+import url from 'url';
+const myURL = new URL('https://a:b@測試?abc#foo');
+
+console.log(myURL.href);
+// Prints https://a:b@xn--g6w251d/?abc#foo
+
+console.log(myURL.toString());
+// Prints https://a:b@xn--g6w251d/?abc#foo
+
+console.log(url.format(myURL, { fragment: false, unicode: true, auth: false }));
+// Prints 'https://測試/?abc'
+```
+
+```cjs
+const url = require('url');
 const myURL = new URL('https://a:b@測試?abc#foo');
 
 console.log(myURL.href);
@@ -1023,17 +1057,28 @@ added: v10.12.0
 This function ensures that `path` is resolved absolutely, and that the URL
 control characters are correctly encoded when converting into a File URL.
 
-```js
-new URL(__filename);                // Incorrect: throws (POSIX)
-new URL(__filename);                // Incorrect: C:\... (Windows)
-pathToFileURL(__filename);          // Correct:   file:///... (POSIX)
-pathToFileURL(__filename);          // Correct:   file:///C:/... (Windows)
+```mjs
+import { pathToFileURL } from 'url';
 
-new URL('/foo#1', 'file:');         // Incorrect: file:///foo#1
-pathToFileURL('/foo#1');            // Correct:   file:///foo%231 (POSIX)
+new URL('/foo#1', 'file:');           // Incorrect: file:///foo#1
+pathToFileURL('/foo#1');              // Correct:   file:///foo%231 (POSIX)
 
-new URL('/some/path%.c', 'file:'); // Incorrect: file:///some/path%.c
-pathToFileURL('/some/path%.c');    // Correct:   file:///some/path%25.c (POSIX)
+new URL('/some/path%.c', 'file:');    // Incorrect: file:///some/path%.c
+pathToFileURL('/some/path%.c');       // Correct:   file:///some/path%25.c (POSIX)
+```
+
+```cjs
+const { pathToFileURL } = require('url');
+new URL(__filename);                  // Incorrect: throws (POSIX)
+new URL(__filename);                  // Incorrect: C:\... (Windows)
+pathToFileURL(__filename);            // Correct:   file:///... (POSIX)
+pathToFileURL(__filename);            // Correct:   file:///C:/... (Windows)
+
+new URL('/foo#1', 'file:');           // Incorrect: file:///foo#1
+pathToFileURL('/foo#1');              // Correct:   file:///foo%231 (POSIX)
+
+new URL('/some/path%.c', 'file:');    // Incorrect: file:///some/path%.c
+pathToFileURL('/some/path%.c');       // Correct:   file:///some/path%25.c (POSIX)
 ```
 
 ## Legacy URL API
@@ -1190,6 +1235,7 @@ The `url.format()` method returns a formatted URL string derived from
 `urlObject`.
 
 ```js
+const url = require('url');
 url.format({
   protocol: 'https',
   hostname: 'example.com',