(maint) Add new fact-nodes endpoint to v4, and re-order sensibly

This adds the endpoint `fact-nodes` to the index for master, and re-orders the
indexes so that like components are next to each other.

Signed-off-by: Ken Barber <ken@bob.sh>
Merge pull request #363 from kbarber/maint/master/pdb-add-new-index-for-fact-nodes

(maint) Add new fact-nodes endpoint to v4, and re-order sensibly