[fix] reorganize the typing files

types/docs.type.ts

@@ -0,0 +1,23 @@
+import type { TPostFrontmatter } from "./frontmatter.type";
+
+export type TPostListItem = {
+  id: string;
+  frontMatter: TPostFrontmatter;
+};
+
+export type TPostsByTag = {
+  [tagName: string]: TPostListItem[];
+};
+
+export type TSearchResultItem = {
+  id: string;
+  title: string;
+  summary: string | null;
+  tags: string[] | null;
+};
+
+export type TTOCItem = {
+  level: number;
+  title: string;
+  anchorId: string;
+};