[x] read up on ULO/RDF features again

- It's mostly about file structure/organization (duh)

- It also contains slightly deeper links, e.g. about on what objects
  other things are defined.

- In the end it's all about links. There are some data properties but
  they are honestly not that interesting. They are necessary for
  lookup however.

doc/timeline/week26.txt

@@ -8,7 +8,7 @@ Week 26 (22.06. - 26.06.)
        Someone actually familiar with the involved tools will have
        more success I am sure.
 
-[ ] endpoint: read up on ULO/RDF features
+[x] endpoint: read up on ULO/RDF features
 
 [ ] endpoint: set up basic SPARQL endpoint, documentation is probably
     the most important here