添加Open Graph协议内容，让分享博客链接有预览

Gmeek.py

@@ -136,6 +136,11 @@ class GMEEK():
             issue["script"]=issue["script"]+'<script>MathJax = {tex: {inlineMath: [["$", "$"]]}};</script><script async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>'
 
         postBase["postTitle"]=issue["postTitle"]
+        postBase["postUrl"]=self.blogBase["homeUrl"]+"/"+issue["postUrl"]
+        postBase["description"]=issue["description"]
+        postBase["createdDate"]=issue["createdDate"]
+        postBase["author"]=self.blogBase["title"]
+        postBase["avatarUrl"]=self.blogBase["avatarUrl"]
         postBase["postBody"]=post_body
         postBase["commentNum"]=issue["commentNum"]
         postBase["style"]=issue["style"]

templates/post.html

@@ -1,7 +1,13 @@
 {% extends 'base.html' %}
 
 {% block head %}
-<meta name="description" content="{{ blogBase['postTitle'] }}">
+<meta name="description" content="{{ blogBase['description'] }}">
+<meta property="og:title" content="{{ blogBase['postTitle'] }}">
+<meta property="og:type" content="article">
+<meta property="og:url" content="{{ blogBase['postUrl'] }}">
+<meta property="og:image" content="{{ blogBase['avatarUrl'] }}" />
+<meta property="article:published_time" content="{{ blogBase['createdDate'] }}">
+<meta property="article:author" content="{{ blogBase['author'] }}">
 <title>{{ blogBase['postTitle'] }}</title>
 {% if blogBase['highlight']==1 %}<link href="//unpkg.com/@wooorm/starry-night@2.1.1/style/both.css" rel="stylesheet" />{% endif %}
 {% endblock %}