docs/template: (minor detail) redundant "base_news.html, base_news.html"

[marc-medley]

The Stencil/docs/templates.rst pages provides a rendunant example in the last section.

For example, base_news.html, base_news.html.

Perhaps, "base_blog.html, base_news.html" could add more clarity to the "For example, …"?