extra characters

BUR #35793 has been approved by @evazion.

create alias ryuuguu_phaser -> ryugu_phaser
create alias ryuuguu_tremolo -> ryugu_tremelo

extra letter removal

Just to provide some background, the "extra letters" are due to the double vowels present in "りゅうぐう." However, it is romanized as "Ryugu," with no macron above the vowels, on Anime News Network.

The bulk update request #35793 (forum #331568) has been approved by @evazion.