doc: add examples for WHATWG URL objects

doc/api/url.md

@@ -67,6 +67,31 @@ const myURL =
   url.parse('https://user:pass@sub.example.com:8080/p/a/t/h?query=string#hash');
 ```
 
+### Constructing a URL from component parts and getting the constructed string
+
+It is possible to construct a WHATWG URL from component parts using either the
+property setters or a template literal string:
+
+```js
+const myURL = new URL('https://example.org');
+myURL.pathname = '/a/b/c';
+myURL.search = '?d=e';
+myURL.hash = '#fgh';
+```
+
+```js
+const pathname = '/a/b/c';
+const search = '?d=e';
+const hash = '#fgh';
+const myURL = new URL(`https://example.org${pathname}${search}${hash}`);
+```
+
+To get the constructed URL string, use the `href` property accessor:
+
+```js
+console.log(myURL.href);
+```
+
 ## The WHATWG URL API
 
 ### Class: `URL`