refactor(font): scaffold dualFontLayout module with shared types

src/entities/Font/lib/dualFontLayout/index.ts

@@ -0,0 +1,8 @@
+export type {
+    ComparisonLine,
+    ComparisonResult,
+} from './DualFontLayout/DualFontLayout';
+export {
+    computeLineRenderModel,
+    type LineRenderModel,
+} from './computeLineRenderModel/computeLineRenderModel';