Add note about possibility of changing attributes

source/index.html.md

@@ -28,6 +28,7 @@ While we won't be introducing any major changes, we do plan to add new features
 * Adding new resources or endpoints
 * Adding of new (optional) query parameters
 * Changes to the default page length for paginated resources
+* Changes to the attributes of individual fields (including adding/removing/modifying values). Updated lists can be retrieved via the attributes endpoint (see dedicated section).
 
 Please bear this in mind when programming against our API, and try to ensure that these non-breaking changes don't break your code.