Migrate custom BEM to getBEM syntax

Author: anselmbradford

CHANGELOG.md

@@ -585,7 +585,7 @@
 #### Enhancement
 
 * `cfpb-icons`
-  * [#1611](https://github.com/cfpb/design-system/pull/1611) Add `.cf-icon-svg__updating-round` ([@anselmbradford](https://github.com/anselmbradford))
+  * [#1611](https://github.com/cfpb/design-system/pull/1611) Add `.cf-icon-svg--updating-round` ([@anselmbradford](https://github.com/anselmbradford))
 
 #### Internal
 

docs/_includes/footer.html

@@ -2,7 +2,7 @@
 
     <hr>
 
-    <div class="block block__sub ds-footer_content">
+    <div class="block block--sub ds-footer__content">
         <p>
             <small>
                 We need your help keeping the Design System accurate and up-to-date!