DOC: Only list "Active" NEPs under "Meta-NEPs"
DOC: Only list "Active" NEPs under "Meta-NEPs"

In particular, NEP 23 (which is only a draft) is currently listed under both
"Meta-NEPs" *and* "Open NEPs". It should only be in the later.

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