RTL - Persian Language Support

[iarata]

Currently, Index and 404 are done.
The CSS styling supporting the RTL language has been added (tested on the above pages).

Since the site doesn't support RTL, at this moment I think it would be better to have a separate branch for RTL support until all pages or a v.1 support is released.

I also saw the #139 but only translation and no CSS support.

[iarata]

A separate rtl.less file is created to write the RTL support there.
Current idea is to add the RTL class name is added based on the props.name + -rtl like blog-rtl and getting-started-rt in the content-region tag