add missing public methods
Merge branch 'fix/752'
Close #752

* fix/752:
  fix link and add missing public methods
Merge branch 'master' of https://github.com/zendframework/zf2-documentation

* 'master' of https://github.com/zendframework/zf2-documentation:
  fixed typo
  add missing public methods for Zend\Form\Element\Element
  changed bold markdown for inline code
  Fixed examples about quotes filtering
  Fixed lines with more than 115 characters
  Several fixes for Zend\Filter docs
  Minor fixes for i18n filters docs
  Trimmed trailing whitespaces
Merge branch 'translation/761'
Close #761

* translation/761:
  Translated to dutch
Merge branch 'hotfix/#749'
Merge branch 'fix/zend-form-element-checkbox' of https://github.com/robertbasic/zf2-documentation into hotfix/#750
added return type
Merge branch 'hotfix/#750' into develop