edit readme & site config example

README.md

@@ -107,7 +107,19 @@ disqus_shortname:
 - **location** - Where you live in.
 - **disqus_shortname** - Your Disqus shortname.
 
-## Custom Categories & Tags Pages
+### Post Thumbnail & Banner
+
+You can add a thumbnail and a banner to each post by adding the following lines into your post source files' front-matter:
+```r
+title: Demo
+date: 2015-01-01
+...
+# add those
+thumbnail: http://example.com/thumbnail.jpg
+banner: http://example.com/banner.jpg
+```
+
+### Custom Categories & Tags Pages
 
 To enable custom categories page and tags page, just copy the `categories` folder and `tags` folder under your theme's `_source` foler into your site's `source` folder. Then edit theme's _config.yml and add the following lines: 
 ```r
@@ -119,7 +131,7 @@ menu:
   ...
 ```
 
-## Languages
+### Languages
 
 English and Simplified Chinese are the default languages of the theme. You can add translations in the `languages` folder and change the default language in blog's `_config.yml`.
 

_config.yml.site.example

@@ -13,6 +13,7 @@ location: 'Harbin, China'
 follow: https://github.com/ppoffice/
 language: en
 timezone:
+since: 2000 # The start year showing in your copyright section.
 
 # URL
 ## If your site is put in a subdirectory, set url as 'http://yoursite.com/child' and root as '/child/'