[doc] add missing doc for datatset (#3487)
[doc] add missing doc for datatset (#3487)


openthread/openthread,turon/openthread,chshu/openthread,bukepo/openthread,erja-gp/openthread,chshu/openthread,jwhui/openthread,openthread/openthread,librasungirl/openthread,srickardti/openthread,jwhui/openthread,chshu/openthread,openthread/openthread,librasungirl/openthread,turon/openthread,abtink/openthread,srickardti/openthread,bukepo/openthread,lanyuwen/openthread,abtink/openthread,abtink/openthread,abtink/openthread,erja-gp/openthread,erja-gp/openthread,bukepo/openthread,lanyuwen/openthread,librasungirl/openthread,chshu/openthread,lanyuwen/openthread,lanyuwen/openthread,turon/openthread,jwhui/openthread,erja-gp/openthread,erja-gp/openthread,erja-gp/openthread,srickardti/openthread,jwhui/openthread,turon/openthread,chshu/openthread,librasungirl/openthread,lanyuwen/openthread,openthread/openthread,lanyuwen/openthread,bukepo/openthread,chshu/openthread,srickardti/openthread