CLN: DataFrame move doc from __init__ to cls
CLN: DataFrame move doc from __init__ to cls

This commit moves the doc string to a more common location.

gfyoung/pandas,MJuddBooth/pandas,toobaz/pandas,harisbal/pandas,nmartensen/pandas,MJuddBooth/pandas,linebp/pandas,gfyoung/pandas,pandas-dev/pandas,rs2/pandas,cython-testbed/pandas,linebp/pandas,jorisvandenbossche/pandas,pandas-dev/pandas,DGrady/pandas,toobaz/pandas,jreback/pandas,zfrenchee/pandas,zfrenchee/pandas,pratapvardhan/pandas,jreback/pandas,dsm054/pandas,MJuddBooth/pandas,harisbal/pandas,GuessWhoSamFoo/pandas,kdebrab/pandas,rs2/pandas,nmartensen/pandas,Winand/pandas,pratapvardhan/pandas,DGrady/pandas,jorisvandenbossche/pandas,GuessWhoSamFoo/pandas,Winand/pandas,rs2/pandas,GuessWhoSamFoo/pandas,toobaz/pandas,cython-testbed/pandas,louispotok/pandas,linebp/pandas,winklerand/pandas,DGrady/pandas,amolkahat/pandas,winklerand/pandas,amolkahat/pandas,cython-testbed/pandas,winklerand/pandas,MJuddBooth/pandas,pandas-dev/pandas,MJuddBooth/pandas,datapythonista/pandas,kdebrab/pandas,TomAugspurger/pandas,pratapvardhan/pandas,datapythonista/pandas,linebp/pandas,nmartensen/pandas,jorisvandenbossche/pandas,zfrenchee/pandas,kdebrab/pandas,linebp/pandas,cython-testbed/pandas,amolkahat/pandas,DGrady/pandas,louispotok/pandas,amolkahat/pandas,DGrady/pandas,harisbal/pandas,harisbal/pandas,Winand/pandas,datapythonista/pandas,zfrenchee/pandas,GuessWhoSamFoo/pandas,Winand/pandas,jmmease/pandas,amolkahat/pandas,datapythonista/pandas,cbertinato/pandas,Winand/pandas,linebp/pandas,pandas-dev/pandas,GuessWhoSamFoo/pandas,jreback/pandas,winklerand/pandas,nmartensen/pandas,jmmease/pandas,zfrenchee/pandas,cython-testbed/pandas,kdebrab/pandas,jmmease/pandas,jorisvandenbossche/pandas,jreback/pandas,cbertinato/pandas,pratapvardhan/pandas,Winand/pandas,winklerand/pandas,TomAugspurger/pandas,dsm054/pandas,winklerand/pandas,nmartensen/pandas,dsm054/pandas,louispotok/pandas,cbertinato/pandas,TomAugspurger/pandas,gfyoung/pandas,jmmease/pandas,louispotok/pandas,dsm054/pandas,TomAugspurger/pandas,pratapvardhan/pandas,toobaz/pandas,DGrady/pandas,gfyoung/pandas,dsm054/pandas,gfyoung/pandas,jreback/pandas,kdebrab/pandas,jmmease/pandas,cbertinato/pandas,toobaz/pandas,jmmease/pandas,cbertinato/pandas,nmartensen/pandas,rs2/pandas,louispotok/pandas,harisbal/pandas