Replace all DOS line endings with Unix

Command run was:
git ls-tree -r HEAD --name-only | xargs dos2unix

docs/en/languages.rst

@@ -1,19 +1,19 @@
-Switch Between Languages/切换语言
-=================================
-
-The documentation now has two language versions, however, please refer to the English version if there is any discrepancy.
-
-本文档现在有两种语言的版本，如有出入请以英文版本为准。
-
-- English/英文
-- Chinese/中文
-
-You can easily changed from one language to another by the panel on the sidebar like below. Just click on the **Read
-the Docs** title button on the left-bottom conner if it is folded.
-
-如下图所示，你可使用边栏的面板进行语言的切换。如果该面板被折叠，点击左下角 **Read the Docs** 标题按钮来显示它。
-
-.. image:: /../_static/choose_version.png
-
-
-
+Switch Between Languages/切换语言
+=================================
+
+The documentation now has two language versions, however, please refer to the English version if there is any discrepancy.
+
+本文档现在有两种语言的版本，如有出入请以英文版本为准。
+
+- English/英文
+- Chinese/中文
+
+You can easily changed from one language to another by the panel on the sidebar like below. Just click on the **Read
+the Docs** title button on the left-bottom conner if it is folded.
+
+如下图所示，你可使用边栏的面板进行语言的切换。如果该面板被折叠，点击左下角 **Read the Docs** 标题按钮来显示它。
+
+.. image:: /../_static/choose_version.png
+
+
+