Add documentation for AtkKeyEventType

Add documentation for AtkKeyEventType

*  atk/atkutil.h: Add documentation for AtkKeyEventType

* docs/tmpl/action.sgml docs/tmpl/atkcomponent.sgml
docs/tmpl/atkdocument.sgml docs/tmpl/atkeditabletext.sgml
docs/tmpl/atkgobjectaccessible.sgml docs/tmpl/atkhyperlink.sgml
docs/tmpl/atkhypertext.sgml docs/tmpl/atkimage.sgml
docs/tmpl/atknoopobject.sgml docs/tmp[l/atknoopobjectfactory.sgml
docs/tmpl/atkobject.sgml docs/tmpl/atkobjectfacory.sgml
docs/tmpl/atkregistry.sgml docs/tmpl/atkrelation.sgml
docs/tmpl/atkselection.sgml docs/tmpl/atkstate.sgml
docs/tmpl/atkstreamablecontent.sgml docs/tmpl/atktable.sgml
docs/tmpl/atktext.sml docs/tmpl/atkutil.sgml
docs/tmpl/atkutil.sgml:
Reduce number of undocumented symbols