DOC: update the DataFrame.count docstring (#20221)
DOC: update the DataFrame.count docstring (#20221)

* DataFrame.count docstring reworked, examples added

* review corrections

* review fixes + better description

* review fixes, full stop and backticks

* review fix: changed summary, added quoting

dsm054/pandas,pandas-dev/pandas,jreback/pandas,GuessWhoSamFoo/pandas,rs2/pandas,cbertinato/pandas,dsm054/pandas,rs2/pandas,datapythonista/pandas,harisbal/pandas,amolkahat/pandas,cython-testbed/pandas,MJuddBooth/pandas,datapythonista/pandas,jreback/pandas,MJuddBooth/pandas,pandas-dev/pandas,rs2/pandas,jorisvandenbossche/pandas,pratapvardhan/pandas,louispotok/pandas,cbertinato/pandas,jorisvandenbossche/pandas,pratapvardhan/pandas,jreback/pandas,gfyoung/pandas,cbertinato/pandas,dsm054/pandas,MJuddBooth/pandas,TomAugspurger/pandas,cython-testbed/pandas,MJuddBooth/pandas,kdebrab/pandas,gfyoung/pandas,pandas-dev/pandas,rs2/pandas,harisbal/pandas,amolkahat/pandas,toobaz/pandas,kdebrab/pandas,pandas-dev/pandas,toobaz/pandas,cbertinato/pandas,cython-testbed/pandas,GuessWhoSamFoo/pandas,datapythonista/pandas,toobaz/pandas,pratapvardhan/pandas,harisbal/pandas,jreback/pandas,amolkahat/pandas,jreback/pandas,harisbal/pandas,dsm054/pandas,MJuddBooth/pandas,louispotok/pandas,harisbal/pandas,cython-testbed/pandas,TomAugspurger/pandas,GuessWhoSamFoo/pandas,gfyoung/pandas,GuessWhoSamFoo/pandas,louispotok/pandas,jorisvandenbossche/pandas,datapythonista/pandas,kdebrab/pandas,pratapvardhan/pandas,pratapvardhan/pandas,cbertinato/pandas,cython-testbed/pandas,kdebrab/pandas,gfyoung/pandas,amolkahat/pandas,toobaz/pandas,louispotok/pandas,jorisvandenbossche/pandas,toobaz/pandas,TomAugspurger/pandas,amolkahat/pandas,louispotok/pandas,kdebrab/pandas,GuessWhoSamFoo/pandas,dsm054/pandas,TomAugspurger/pandas,gfyoung/pandas