Clear out non-v4 docs translations

After v4.0.0 stable gets released, as existing translations get updated or completely new v4 translations get created, we can start adding entries back to the list.

docs/_data/translations.yml

@@ -2,58 +2,3 @@
   code: zh
   description: Bootstrap 中文文档
   url: http://v4.bootcss.com/
-
-- name: Danish
-  code: da
-  description: Bootstrap på Dansk
-  url: http://getbootstrap.dk/
-
-- name: French
-  code: fr
-  description: Bootstrap en Français
-  url: http://www.oneskyapp.com/fr/docs/bootstrap/getting-started/
-
-- name: German
-  code: de
-  description: Bootstrap auf Deutsch
-  url: http://holdirbootstrap.de/
-
-- name: Italian
-  code: it
-  description: Bootstrap in Italiano
-  url: http://www.hackerstribe.com/guide/IT-bootstrap-3.1.1/
-
-- name: Korean
-  code: ko
-  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
-  url: http://www.oneskyapp.com/ru/docs/bootstrap/
-
-- name: Spanish
-  code: es
-  description: Bootstrap en Español
-  url: http://www.oneskyapp.com/es/docs/bootstrap/
-
-- name: Turkish
-  code: tr
-  description: Türkçe Bootstrap
-  url: http://www.trbootstrap.com
-
-- name: Ukrainian
-  code: uk
-  description: Bootstrap українською
-  url: http://twbs.docs.org.ua
-
-- name: Vietnamese
-  code: vi
-  description: Bootstrap bằng tiếng Việt
-  url: http://getbootstrap.com.vn