change version selector position

[ddcat1115]

to make it easier to be found.

[mention-bot]

@ddcat1115, thanks for your PR! By analyzing the history of the files in this pull request, we identified @afc163, @benjycui and @pinggod to be potential reviewers.

[coveralls]

Coverage remained the same at 82.442% when pulling 1f31688 on ddcat1115:version-pos into 637c479 on ant-design:master.

[afc163]

把语言切换也改成 select，然后再加个国旗好了。

[benjycui]

其实只有两个语言时的语言切换，还是不要用 Select。

这样英文不好的人就真的不知道要点哪里了。。

[ddcat1115]

😂 是的......加个国旗可能会好些，但是select更宽，目前 component search 都已经很难露脸了。。。。两种语言时就维持现状操作起来也更简单

[ddcat1115]

先合了，后面有需要再改~