chore(meta): rename to vk-x

Rename from "Your New Jekyll Site" to "vk-x".
style(index): add newline at eof
feat(index): rename index.html to index.md

You know what this means.
feat(default layout): apply Twitter Bootstrap

Add Bootstrap CSS and JS (also jQuery as a dependency).
See: http://getbootstrap.com/
feat(default layout): add header navbar

- remove default "Blog Posts" content
- remove default footer
- add `current_language` yaml variable (equals `en` on index.md)
- add `ru/index.md` file with `current_language` set to `ru`
- add `_includes/header.html` and `_includes/header_ru.html`
feat(index): add logo, description, "install" button