DOC: Include NEP titles for first reference in NEP 42
DOC: Include NEP titles for first reference in NEP 42

Rather than saying 'NEP 4x', the links
in the note at the top now include the NEP titles as well.

pdebuyl/numpy,endolith/numpy,pdebuyl/numpy,mattip/numpy,grlee77/numpy,madphysicist/numpy,mattip/numpy,pdebuyl/numpy,jakirkham/numpy,pbrod/numpy,rgommers/numpy,madphysicist/numpy,jakirkham/numpy,endolith/numpy,mhvk/numpy,numpy/numpy,grlee77/numpy,numpy/numpy,grlee77/numpy,charris/numpy,numpy/numpy,anntzer/numpy,mattip/numpy,mhvk/numpy,mhvk/numpy,endolith/numpy,mattip/numpy,jakirkham/numpy,anntzer/numpy,grlee77/numpy,charris/numpy,pbrod/numpy,mhvk/numpy,rgommers/numpy,rgommers/numpy,seberg/numpy,charris/numpy,simongibbons/numpy,anntzer/numpy,seberg/numpy,simongibbons/numpy,madphysicist/numpy,seberg/numpy,grlee77/numpy,charris/numpy,pbrod/numpy,simongibbons/numpy,numpy/numpy,endolith/numpy,pbrod/numpy,rgommers/numpy,pbrod/numpy,mhvk/numpy,jakirkham/numpy,madphysicist/numpy,seberg/numpy,jakirkham/numpy,anntzer/numpy,pdebuyl/numpy,simongibbons/numpy,madphysicist/numpy,simongibbons/numpy