Add trailing-slash example to URL href docs (mdn#43018)

* Add trailing-slash example to URL href docs

* Fixes

* Update

---------

Co-authored-by: Joshua Chen <sidachen2003@gmail.com>

Author: badwriter123

files/en-us/web/api/url/href/index.md

@@ -17,11 +17,22 @@ A string.
 
 ## Examples
 
+### Full URL with path
+
 ```js
 const url = new URL(
   "https://developer.mozilla.org/en-US/docs/Web/API/URL/href",
 );
-console.log(url.href); // Logs: 'https://developer.mozilla.org/en-US/docs/Web/API/URL/href'
+console.log(url.href); // https://developer.mozilla.org/en-US/docs/Web/API/URL/href
+```
+
+### Origin-only URL
+
+For [hierarchical schemes](https://www.rfc-editor.org/rfc/rfc3986#section-1.2.3) such as `https:`, the pathname must always be non-empty. When the URL has no path (for example, only an origin), the URL parser sets the pathname to `"/"`, so `href` includes a trailing slash. See the {{domxref("URL/pathname", "pathname")}} property for more details.
+
+```js
+const url = new URL("https://developer.mozilla.org");
+console.log(url.href); // https://developer.mozilla.org/
 ```
 
 ## Specifications
@@ -35,3 +46,4 @@ console.log(url.href); // Logs: 'https://developer.mozilla.org/en-US/docs/Web/AP
 ## See also
 
 - The {{domxref("URL")}} interface it belongs to.
+- {{domxref("URL.pathname")}}