DOC: Removed broken link
DOC: Removed broken link

Removed a broken link from the subclassing ndarray in the user guide.

Removed credit to Pierre Gerard-Marchant, as this is out of place in the user guide. #8673
WarrenWeckesser/numpy,ahaldane/numpy,charris/numpy,jakirkham/numpy,pizzathief/numpy,grlee77/numpy,bringingheavendown/numpy,tynn/numpy,seberg/numpy,seberg/numpy,pbrod/numpy,pbrod/numpy,MSeifert04/numpy,solarjoe/numpy,ssanderson/numpy,madphysicist/numpy,simongibbons/numpy,WarrenWeckesser/numpy,abalkin/numpy,grlee77/numpy,tynn/numpy,grlee77/numpy,abalkin/numpy,bertrand-l/numpy,Eric89GXL/numpy,gfyoung/numpy,madphysicist/numpy,MSeifert04/numpy,mhvk/numpy,gfyoung/numpy,jakirkham/numpy,madphysicist/numpy,endolith/numpy,anntzer/numpy,pizzathief/numpy,numpy/numpy,endolith/numpy,solarjoe/numpy,ahaldane/numpy,jakirkham/numpy,behzadnouri/numpy,anntzer/numpy,Eric89GXL/numpy,pdebuyl/numpy,ssanderson/numpy,numpy/numpy,rgommers/numpy,simongibbons/numpy,MSeifert04/numpy,bertrand-l/numpy,madphysicist/numpy,pizzathief/numpy,jorisvandenbossche/numpy,jorisvandenbossche/numpy,WarrenWeckesser/numpy,WarrenWeckesser/numpy,abalkin/numpy,chatcannon/numpy,chatcannon/numpy,charris/numpy,grlee77/numpy,pbrod/numpy,pbrod/numpy,ahaldane/numpy,b-carter/numpy,grlee77/numpy,pizzathief/numpy,WarrenWeckesser/numpy,mhvk/numpy,behzadnouri/numpy,pbrod/numpy,shoyer/numpy,shoyer/numpy,ahaldane/numpy,shoyer/numpy,mhvk/numpy,shoyer/numpy,anntzer/numpy,Eric89GXL/numpy,MSeifert04/numpy,bringingheavendown/numpy,bringingheavendown/numpy,anntzer/numpy,simongibbons/numpy,pizzathief/numpy,pdebuyl/numpy,mhvk/numpy,simongibbons/numpy,jakirkham/numpy,mhvk/numpy,pdebuyl/numpy,seberg/numpy,charris/numpy,madphysicist/numpy,pdebuyl/numpy,seberg/numpy,mattip/numpy,rgommers/numpy,behzadnouri/numpy,endolith/numpy,MSeifert04/numpy,simongibbons/numpy,jakirkham/numpy,jorisvandenbossche/numpy,Eric89GXL/numpy,charris/numpy,mattip/numpy,solarjoe/numpy,b-carter/numpy,chatcannon/numpy,shoyer/numpy,mattip/numpy,tynn/numpy,jorisvandenbossche/numpy,rgommers/numpy,ahaldane/numpy,b-carter/numpy,numpy/numpy,endolith/numpy,bertrand-l/numpy,ssanderson/numpy,jorisvandenbossche/numpy,mattip/numpy,numpy/numpy,gfyoung/numpy,rgommers/numpy