Add Brazilian Portuguese to list of docs translations

Closes #16773 by merging a tweaked version of it.
[skip sauce]

docs/_data/translations.yml

@@ -28,6 +28,11 @@
   description: Bootstrap 한국어
   url: http://bootstrapk.com/
 
+- name: Brazilian Portuguese
+  code: pt-BR
+  description: Bootstrap em Português do Brasil
+  url: http://bootstrapbrasil.github.io/
+
 - name: Russian
   code: ru
   description: Bootstrap по-русски