Blog links should show meaningful link previews

[nairbv]

When sharing links to the pytorch blog, social media and messenger apps show a "link preview" that typically summarizes what can be found at the URL. Link previews to pytorch.org blog posts are pretty minimal. These previews would be more effective if they showed more info, such as the title of the blog.

[cjyabraham]

I believe I fixed this in this PR. If you find it's not fixed, please reopen.

[nairbv]

I believe I fixed this in this PR. If you find it's not fixed, please reopen.

looks good, thanks