Remove publish date#94

As Bear can be used for much more than Blogging, Users should be able to remove the published_date - Tag so that no date is displayed.

Especially useful for for cross-breed websites which both use blog entries, for which a date is useful, and general purpose pages, for whic dates are irrelevant.

This can be done in 2 ways:

The first is to set is_page: True where it denotes the post as a page.

The second way is to hide the date with CSS by selecting the element and setting its diusplay to none.

time {
  display: none;
}