Consider hiding "partial" snips

[floehopper]

Currently all snips are publicly accessible even if they are not marked as pages using the is_page metadata attribute. The latter just means the page doesn't show up in the sitemap or in any lists of snips.

Some snips (e.g company-info) are clearly not intended for use as a standalone page and I think it would be better if they were not publicly accessible.

One way to achieve this might be to create a separate "soup" like I've already done for the snips in soups/templates, perhaps soups/shared or soups/partial.