feat: use <time> tag

helps with accessibility.

see: https://developer.mozilla.org/ko/docs/Web/HTML/Element/time

Author: scarf005

_includes/blog-list.html

@@ -16,7 +16,7 @@
 					{% for post in paginator.posts %}
 						<div class="blog-item">
 							<h2><a href="{{post.url}}">{{post.title}}</a></h2>
-							<p class="blog-date">{{post.date | date: "%A %-d %B %Y"}}</p>
+							<time datetime="{{post.date}}" class="blog-date">{{post.date | date: "%A %-d %B %Y"}}</time>
 							{% if post.by %}<p class="blog-author">{{post.by}}</p>{% endif %}
 							{% if post.tags %}
 								<ul class="tag-list">

_includes/inner-page-blog-detail-main-content.html

@@ -4,7 +4,7 @@
 			<div class="inner-box">
 				<div class="blog-detail-head">
 					<div>
-						<p>{{page.date | date: "%A %-d %B %Y"}}</p>
+						<time datetime="{{page.date}}">{{page.date | date: "%A %-d %B %Y"}}</time>
 						<p>{{page.by}}</p>
 					</div>
 					{% if page.tags %}

_layouts/blog.html

@@ -3,7 +3,7 @@
 ---
 
 <div class="main-page-column">
-  <div class="article-date">{{ page.date | date: "%B %-d, %Y" }}</div>
+  <time datetime="{{page.date}}" class="article-date">{{ page.date | date: "%B %-d, %Y" }}</time>
   {% if page.by %}
     <div class="written">Written By: <span class="by">{{ page.by }}</span></div>
   {% endif %}