Because the confetti rained down after he gained the 86th Scripps Spelling Bee on Thursday evening, Arvind Mahankali, thirteen, used to be calm. “It hadn’t completely registered yet that I had received so I didn’t really savour the magnitude of what had simply happened,’’ Mahankali stated on TODAY Friday.The teen from Queens, N.Y., took dwelling the title by using spelling the phrase “knaidel,” a German-derived Yiddish word which refers…