Update iso_15924.xml
Update iso_15924.xml

Manual comparison with and update based on the list of codes published on <http://unicode.org/iso15924/>, status of 9 February 2021, 4.30pm CET

Out of the 53 additions since June 2015, five already had been in the file here. The remaining 48 additions are:
Adlam
Caucasian Albanian
Ahom, Tai Ahom
Arabic (Nastaliq variant)
Bhaiksuki
Chorasmian
Cypro-Minoan
Dives Akuru
Dogra
Elimais
Gunjala Gondi
Masaram Gondi
Han with Bopomofo (alias for Han + Bopomofo)
Hatran
Anatolian Hieroglyphs (Luwian Hieroglyphs, Hittite Hieroglyphs)
Nyiakeng Puachue Hmong
Jamo (alias for Jamo subset of Hangul)
Khitan large script
Khitan small script
Leke
Mahajani
Makasar
Marchen
Medefaidrin (Oberi Okaime, Oberi Ɔkaimɛ)
Modi, Moḍī
Multani
Nandinagari
Newa, Newar, Newari, Nepāla lipi
Naxi Dongba (na²¹ɕi³³ to³³ba²¹, Nakhi Tomba)
Osage
Old Uyghur
Pau Cin Hau
Proto-Cuneiform
Proto-Elamite
Klingon (KLI pIqaD)
Proto-Sinaitic
Ranjana
Hanifi Rohingya
Shuishu
Siddham, Siddhaṃ, Siddhamātṛkā
Sogdian
Old Sogdian
Soyombo
Toto
Wancho
Yezidi
Zanabazar Square (Zanabazarin Dörböljin Useg, Xewtee Dörböljin Bicig, Horizontal Square Script)
Symbols (Emoji variant)
SAA-SDT/EAD-Revision,SAA-SDT/EAD3,SAA-SDT/EAD3,SAA-SDT/EAD-Revision