Fixes share_twitter_url error on blog pages.

There were two issues here. The issue that caused this to appear was that I made a recent update that nested the `content` block inside of one called `body` and didn't add the `scoped` attribute. The other issue was that `article.html` was never updated to use the share macro. This PR finally updates `article.html` which also removes the need to import the twitter share macro on every page.