Expand README and tidy templates & VSCode settings

Replace the placeholder README with a full Chinese README for the Halo + Astro theme starter, adding rationale, architecture, dev/build instructions, directory layout, and usage notes. Also apply minor formatting/whitespace cleanups: adjust .vscode/settings.json formatting, collapse attributes on the category list div in src/pages/categories.astro, and remove an extra blank line in src/pages/category.astro. These are documentation and formatting changes only — no functional behavior changes.

src/pages/categories.astro

@@ -8,10 +8,7 @@ import Layout from "../layouts/Layout.astro";
   </Fragment>
 
   <nav class="taxonomy-list" aria-label="Category list">
-    <div
-      th:each="category : ${categories}"
-      class="taxonomy-list__item"
-    >
+    <div th:each="category : ${categories}" class="taxonomy-list__item">
       <a
         class="taxonomy-list__link"
         th:href="@{${category.status.permalink}}"

src/pages/category.astro

@@ -14,7 +14,6 @@ import Layout from "../layouts/Layout.astro";
     </p>
   </div>
 
-  
   <th:block th:replace="~{fragments/post-list}"></th:block>
 
   <div th:if="${posts.total == 0}" class="feed-empty">暂无文章。</div>