Change articles to stories in url structure for articles

[LaurenFBaily]

What

All individual stories should use /stories/ instead of /articles/ and be redirected eg.

https://wellcomecollection.org/articles/ZpoyNhAAAFyEjk becomes www.wellcomecollection/stories/the-wishing-tree-of-loch-maree

Why

Update to match language of the site.

Background

See epic: Descriptive urls