add: U+25A3 ▣ -> e2 96 a3 : WHITE SQUARE CONTAINING BLACK SMALL SQUARE

[ceccopierangiolieugenio]

It seems that this gliph is missing:
add: U+25A3 ▣ -> e2 96 a3 : WHITE SQUARE CONTAINING BLACK SMALL SQUARE

I am using ghostty that should defaults to Jetbrain Mono and I noticed this glitch:

 $ ghostty +show-face --string='▣'
U+25A3 « ▣ » found in face “DejaVuSansM Nerd Font Mono”.

 $ ghostty +show-face --string='□'
U+25A1 « □ » found in face “JetBrains Mono”.

 $ ghostty +show-face --string='a'
U+61 « a » found in face “JetBrains Mono”.