fix: update post layout and change link hover color

src/_includes/post.njk

@@ -2,6 +2,12 @@
 layout: "layout.njk"
 ---
 <article>
+    <div class="mb-8">
+        <a href="/blog">
+        <i class="fas fa-arrow-left mr-2"></i>
+        Back to all posts
+        </a>
+    </div>
     <h1>{{ title }}</h1>
     <p class="text-gray-400">Published on {{ date | readableDate }}</p>
     <br/>