Update accessibility.md (#708)

Fix for broken links to W3C

Author: tsvetta

content/docs/accessibility.md

@@ -203,7 +203,7 @@ initially triggered the modal.
 A more complex user experience should not mean a less accessible one. Whereas accessibility is most easily achieved by coding as close to HTML as possible,
 even the most complex widget can be coded accessibly.
 
-Here we require knowledge of [ARIA Roles](https://www.w3.org/TR/wai-aria/roles) as well as [ARIA States and Properties](https://www.w3.org/TR/wai-aria/states_and_properties). 
+Here we require knowledge of [ARIA Roles](https://www.w3.org/TR/wai-aria/#roles) as well as [ARIA States and Properties](https://www.w3.org/TR/wai-aria/#states_and_properties). 
 These are toolboxes filled with HTML attributes that are fully supported in JSX and enable us to construct fully accessible, highly functional React components.
 
 Each type of widget has a specific design pattern and is expected to function in a certain way by users and user agents alike: