[ghostty] work around bad line heights in Meslo NF

ghostty recently updated font metric calculations to be much more accurate, and I guess it turns out that MesloNF doesn't include the metrics needed to make sure that lines are the right height? this fixes the problem of lines being collapsed and super close to one another.

private_dot_config/private_ghostty/config

···
 config-file = /Users/andre/.config/ghostty/themes/selenized-dark
 font-family = MesloLGS NF
 font-size = 14
+adjust-cell-height = 4
 
 cursor-style = block
 cursor-style-blink = false