Remove core/docs/tutorials

Closes #11573
various design improvements per #11540
give all contexts the same style in the tree
increase padding around the resources list in the tree
Various design improvements

Addresses issues described in #11540

Merge remote-tracking branch 'origin/pr/11574' into develop

* origin/pr/11574:
  increase padding around the resources list in the tree
  give all contexts the same style in the tree
  various design improvements per #11540