See: https://github.com/lerna/lerna/issues/2107

BREAKING CHANGE: please head https://vuepress-theme-blog.ulivz.com/ to see the default blog theme
for vuepress

BREAKING CHANGE: Function of this plugin has been integrated in the fresh official blog plugin:
https://github.com/ulivz/vuepress-plugin-blog

fix($core): cannot retrieve the correct theme name when them path is a local absolute path linked to a javascript file.

We shouldn't let the core render the `.content` class, so once we use custom layout in the default theme, the styles of default theme will pollute the styles of custom layout.