Update label in posts.

_data/label.yml

@@ -16,4 +16,7 @@ panel:
   trending_tags: "Trending Tags"
   toc: "Contents"
 
+post:
+  relate_posts: "Further Reading"
+
 search_hint: "Search"   # text show on search bar

_includes/related-posts.html

@@ -43,7 +43,7 @@
   {% assign score_list = score_list | sort | reverse %}
   {% assign count = 0 %}
   <div id="related-posts" class="mt-4 mb-2 mb-sm-4 pb-2">
-    <h3 class="pt-2 mt-1 mb-4" data-toc-skip>Related Posts</h3>
+    <h3 class="pt-2 mt-1 mb-4" data-toc-skip>{{ site.data.label.post.relate_posts }}</h3>
     <div class="card-deck mb-4">
     {% for score_item in score_list %}
       {% assign data = score_item | split: ":" %}