use iosevka-nf for braille

Author: Yatao Li

ui.fs

@@ -142,19 +142,11 @@ let DefaultFontEmoji =
     elif RuntimeInformation.IsOSPlatform(OSPlatform.OSX)   then "Apple Color Emoji"
     else "Noto Color Emoji"
 
-let DefaultFontBraille =
-    if RuntimeInformation.IsOSPlatform(OSPlatform.Windows) then "Segoe UI Symbol"
-    elif RuntimeInformation.IsOSPlatform(OSPlatform.Linux) then "Monospace" // ?
-    elif RuntimeInformation.IsOSPlatform(OSPlatform.OSX)   then "Menlo" // ?
-    else "Monospace"
-
-
 let private nerd_typeface = 
     let name = if RuntimeInformation.IsOSPlatform(OSPlatform.OSX) then "Iosevka NF"
                else "Iosevka"
     Typeface($"resm:fvim.Fonts.nerd.ttf?assembly=FVim#{name}")
 let private emoji_typeface = Typeface(DefaultFontEmoji)
-let private braille_typeface = Typeface(DefaultFontBraille)
 let private fontcache = System.Collections.Generic.Dictionary<string*bool*bool, Typeface>()
 
 let InvalidateFontCache () =
@@ -190,7 +182,7 @@ let GetTypeface(txt, italic, bold, font, wfont) =
     | CharType.Powerline
     | CharType.Nerd when not states.font_nonerd -> nerd_typeface
     | CharType.Emoji -> emoji_typeface
-    | CharType.Braille -> braille_typeface
+    | CharType.Braille -> nerd_typeface
     | _              -> _get font
 
 let MeasureText (rune: Rune, font: string, wfont: string, fontSize: float, scaling: float) =