update i18n docs for Finnish

examples/docs/en-US/i18n.md

@@ -96,6 +96,7 @@ Currently Element ships with the following languages:
   <li>Indonesian (id)</li>
   <li>Bulgarian (bg)</li>
   <li>Polish (pl)</li>
+  <li>Finnish (fi)</li>
 </ul>
 
 If your target language is not included, you are more than welcome to contribute: just add another language config [here](https://github.com/ElemeFE/element/tree/master/src/locale/lang) and create a pull request.

examples/docs/zh-CN/i18n.md

@@ -108,6 +108,7 @@ Vue.use(Element, {
   <li>印尼语（id）</li>
   <li>保加利亚语（bg）</li>
   <li>波兰语（pl）</li>
+  <li>芬兰语（fi）</li>
 </ul>
 
 如果你需要使用其他的语言，欢迎贡献 PR：只需在 [这里](https://github.com/ElemeFE/element/tree/master/src/locale/lang) 添加一个语言配置文件即可。