fix: 補全新增的配置

improvement: Open_Graph 改為 hexo 內置 生成
feat: 增加 tag_per_img 配置（可為各個tag 單獨配置top_img）
feat: 增加 category_per_img 配置（可為各個category單獨配置top_img）

_config.yml

@@ -94,23 +94,33 @@ avatar:
   img:
   effect: false
 
-# the banner image of home page
+# The banner image of home page
 index_img:
 
-# if the banner of page not setting, it will show the top_img
+# If the banner of page not setting, it will show the top_img
 default_top_img:
 
-# the banner image of archive page
+# The banner image of archive page
 archive_img:
 
-# the banner image of tag page
+# If the banner of tag page not setting, it will show the top_img
 # note: tag page, not tags page (子標籤頁面的 top_img)
 tag_img:
 
-# the banner image of category page
+# The banner image of tag page
+# format: 
+#  - tag name: xxxxx
+tag_per_img:
+
+# If the banner of category page not setting, it will show the top_img
 # note: category page, not categories page (子分類頁面的 top_img)
 category_img:
 
+# The banner image of category page
+# format: 
+#  - category name: xxxxx
+category_per_img:
+
 # If you are using hexo-douban, you can configure it (如果你有使用 hexo-douban,可配置這個)
 # douban:
 #   meta: false