[docs] update Doxygen for otMacCounters (#4622)
[docs] update Doxygen for otMacCounters (#4622)


bukepo/openthread,chshu/openthread,bukepo/openthread,openthread/openthread,chshu/openthread,librasungirl/openthread,librasungirl/openthread,chshu/openthread,abtink/openthread,jwhui/openthread,openthread/openthread,abtink/openthread,srickardti/openthread,bukepo/openthread,openthread/openthread,openthread/openthread,lanyuwen/openthread,lanyuwen/openthread,chshu/openthread,librasungirl/openthread,abtink/openthread,jwhui/openthread,bukepo/openthread,librasungirl/openthread,srickardti/openthread,lanyuwen/openthread,chshu/openthread,abtink/openthread,jwhui/openthread,lanyuwen/openthread,srickardti/openthread,lanyuwen/openthread,srickardti/openthread,jwhui/openthread,lanyuwen/openthread,chshu/openthread