feat: add modified datetime in blog posts

* feat: add modified datetime in blog posts

Add modDatetime in blogSchema. Update Datetime component to accept modDatetime. Update sorting logic. Rename datetime to pubDatetime in Datetime component.

Closes: #134

* feat: add published_time & modified_time meta tags

* docs: update related blog posts to be up-to-date

* fix: remove extra spaces in breadcrumbs

src/layouts/Layout.astro

@@ -11,6 +11,8 @@ export interface Props {
   description?: string;
   ogImage?: string;
   canonicalURL?: string;
+  pubDatetime?: Date;
+  modDatetime?: Date;
 }
 
 const {
@@ -19,6 +21,8 @@ const {
   description = SITE.desc,
   ogImage = SITE.ogImage,
   canonicalURL = new URL(Astro.url.pathname, Astro.site).href,
+  pubDatetime,
+  modDatetime,
 } = Astro.props;
 
 const socialImageURL = new URL(
@@ -49,6 +53,24 @@ const socialImageURL = new URL(
     <meta property="og:url" content={canonicalURL} />
     <meta property="og:image" content={socialImageURL} />
 
+    <!-- Article Published/Modified time -->
+    {
+      pubDatetime && (
+        <meta
+          property="article:published_time"
+          content={pubDatetime.toISOString()}
+        />
+      )
+    }
+    {
+      modDatetime && (
+        <meta
+          property="article:modified_time"
+          content={modDatetime.toISOString()}
+        />
+      )
+    }
+
     <!-- Twitter -->
     <meta property="twitter:card" content="summary_large_image" />
     <meta property="twitter:url" content={canonicalURL} />