update zh_CN translation

plugins/poll/config/locales/client.zh_CN.yml

@@ -0,0 +1,15 @@
+# encoding: utf-8
+# This file contains content for the client portion of Discourse, sent out
+# to the Javascript app.
+#
+# To validate this YAML file after you change it, please paste it into
+# http://yamllint.com/
+
+zh_CN:
+  js:
+    poll:
+      voteCount: "%{count} 个投票"
+
+      results:
+        show: 显示结果
+        hide: 隐藏结果

plugins/poll/config/locales/server.zh_CN.yml

@@ -0,0 +1,17 @@
+# encoding: utf-8
+# This file contains content for the server portion of Discourse used by Ruby
+#
+# To validate this YAML file after you change it, please paste it into
+# http://yamllint.com/
+
+zh_CN:
+  activerecord:
+    attributes:
+      post:
+        poll_options: "投票选项"
+  poll:
+    must_contain_poll_options: "必须包含投票选项列表"
+    cannot_have_modified_options: "在开始的五分钟后不能修改。如果需要修改他们，请联系版主。"
+    cannot_add_or_remove_options: "只能被编辑，不能添加或者删除。如果您需要添加或者删除选项，您需要锁定这个主题并创建新的。"
+    prefix: "投票："
+    closed_prefix: "已关闭的投票："