use terse flag syntax

src/hwylterm/bbansi.nim

@@ -427,10 +427,7 @@ when isMainModule:
     flags:
       debug "show debug"
       testCard "show test card"
-      style:
-        T string
-        ? "set style for string"
-        - "s"
+      s|style(string, "set style for string")
     run:
       if testCard: showTestCard()
       for arg in args:

src/hwylterm/chooser.nim

@@ -143,10 +143,7 @@ when isMainModule:
       args seq[string]
     flags:
       demo "show demo"
-      separator:
-        T string
-        help "separator to split items"
-        short "s"
+      s|separator(string, "separator to split items")
     run:
       var items: seq[string]
       if demo: