chore: Updating final Attributes docs for v3

markdown/dev/reference/api/attributes/add/en.md

@@ -1,30 +1,25 @@
 ---
-title: add()
+title: Attributes.add()
 ---
 
+The `Attributes.add()` method adds `value` to the attribute identified by
+`key`.
+
+## Signature
+
 ```js
 Attributes attributes.add(string key, string value)
 ```
 
-Adds `value` to the attribute identified by `key`.
+## Example
+
+```js
+const attr = new Attributes()
+  .add('class', 'classA')
+  .add('class', 'classB')
+```
+
+## Notes
 
 Adding multiple values to the same key will result in them being joined together
 (with a space) when rendering.
-
-```js
-let { Path, paths } = part.shorthand();
-
-// This will render as: class="classA classB"
-paths.demo = new Path();
-paths.demo.attributes.add('class', 'classA');
-paths.demo.attributes.add('class', 'classB');
-
-// This does the same thing:
-paths.demo = new Path()
-  .attr('class', 'classA')
-  .attr('class', 'classB');
-
-// This also has the same result:
-paths.demo = new Path()
-  .attr('class', 'classA classB');
-```