Use post-specific CSS class name

Co-authored-by: Agriya Khetarpal <74401230+agriyakhetarpal@users.noreply.github.com>

Author: stefanv

layouts/partials/posts/post.html

@@ -7,7 +7,7 @@ <h1>{{ .Title }}</h1>
     <h5 class="subtitle">{{ .Params.Subtitle }}</h5>
     {{ end }}
     <div class="post-meta">{{ partial "posts/meta.html" . }}
-      <span class="please-comment">🖊️ Please add your comments <a href="#discourse-comments">below!</a></span>
+      <span class="post-please-comment">🖊️ Please add your comments <a href="#discourse-comments">below!</a></span>
     </div>
     <div class="post-content">
       {{ with $featuredImage }}