Revert "Update features to check related content on article pages."

This reverts commit 81e73595853d9f8f0ef003d60cd302b7de0fb4f2.
Revert "Update the article show template to the new design with related content."

This reverts commit 259e0881767966bbd7cd9b76d60d8ca066da8da6.
Revert "Update the article decorator to be able to access article intro, and content without intro."

This reverts commit faf836e3fd5281d46ea56685c0625ba362bacbac.
Revert "Add xpath targeting the intro paragraph."

This reverts commit 197982677a0fe40f45625ba04fae9d64e2b3ac62.
Revert "Add an html processor for extracting the inner html of a node."

This reverts commit ade4375d1b0917ee1d1e18952d79cd53836d2cc8.
Revert "Modify the related links partial to use real categories and content."

This reverts commit 2c260267df30017d36e12122f5ccd10d0e959b8f.
Revert "Modify the related categories partial to use real categories."

This reverts commit 4e86f06a56bc4e145df75c129a119ac460ca4e3d.
Revert "Update articles to consume the category attribute."

This reverts commit cdf642237375b66b98936268bf480f1b2e53808e.