chore: add import/export for letter spacing constant

src/features/SetupFont/index.ts

@@ -4,6 +4,7 @@ export {
     controlManager,
     DEFAULT_FONT_SIZE,
     DEFAULT_FONT_WEIGHT,
+    DEFAULT_LETTER_SPACING,
     DEFAULT_LINE_HEIGHT,
     FONT_SIZE_STEP,
     FONT_WEIGHT_STEP,

src/features/SetupFont/model/index.ts

@@ -1,6 +1,7 @@
 export {
     DEFAULT_FONT_SIZE,
     DEFAULT_FONT_WEIGHT,
+    DEFAULT_LETTER_SPACING,
     DEFAULT_LINE_HEIGHT,
     FONT_SIZE_STEP,
     FONT_WEIGHT_STEP,