Enable to hide the sidebar of blog and release its space.

[Ouch1978]

For now, even I set blogSidebarCount: 0 to hide the content of the blog sidebar, the content width still not get increase.
I think the user experience will be better if we could get additional width for the content area when the sidebar is hidden just like docs do.

[lex111]

It is unlikely that we can place button to hide sidebar on blog pages, but make sense to increase blog content area a bit (suppose, from col-8 to col-10) if blogSidebarCount = 0.