Fix "Download serialization" in the documentation
In the documentation, in the section "Download serialization", the second "N-Triples" should be removed since it is duplicated and the link goes to the n3 file (also already shown).
In the documentation, in the section "Download serialization", the second "N-Triples" should be removed since it is duplicated and the link goes to the n3 file (also already shown).