feat: add post update date (#243)

* feat: Add article update date

* feat:
1.Hide update time on the homepage;
2.Replace update icon;

* remove iconify-json/mdi

---------

Co-authored-by: liangjianhao <jianhao.liang@sz-sanjiang.com>

src/pages/posts/[...slug].astro

@@ -86,6 +86,7 @@ const jsonLd = {
                 <PostMetadata
                         class="mb-5"
                         published={entry.data.published}
+                        updated={entry.data.updated}
                         tags={entry.data.tags}
                         category={entry.data.category}
                 ></PostMetadata>