Added note about custom view helpers to the main view helpers page
Added note about custom view helpers to the main view helpers page

samsonasik/zf2-documentation,Rud5G/zf2-documentation,akrabat/zf2-documentation,akrabat/zf2-documentation,Rud5G/zf2-documentation,rettal/zf2-documentation,rettal/zf2-documentation,samsonasik/zf2-documentation