Update tutorial on demo site.

_posts/2019-08-09-getting-started.md

@@ -73,16 +73,30 @@ As mentioned above, some files or directories should be removed from your repo:
 
 ## Configuration
 
-Customize the variables in file `_config.yml` as needed.
+Basically, go to `_config.yml` and customize the variables as needed, some of them are typical options:
 
-* Avatar
+* `url`
 
-    The sample avatar is `/assets/img/sample/avatar.jpg`. It should be replaced by your own one. Notice that a huge image file will increase the load time of your site, so keep your avatar size as samll as possible(may be *<https://tinypng.com/>* will help).
+    Set to your website domain and there should be no slash symbol at the tail.
 
-* TimeZone
+
+* `avatar`
+
+    It defines the image file location of avatar. The sample image is `/assets/img/sample/avatar.jpg`, and should be replaced by your own one(a square image). Notice that a huge image file will increase the load time of your site, so keep your avatar image size as samll as possible(may be *<https://tinypng.com/>* will help).
+
+* `timezone`
 
     To ensure that the posts' release date matches the city you live in, please modify the field `timezone` correctly. A list of all available values can be found on [TimezoneConverter](http://www.timezoneconverter.com/cgi-bin/findzone/findzone) or [Wikipedia](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones).
 
+* `theme_mode`
+
+    There are three options for the theme color scheme:
+
+    - **dual**  - The default color scheme will follow the system settings, but if the system does not support dark mode, or the browser does not support `Media Queries Level 5`, the theme will be displayed as `light` mode by default. Anyway, the bottom left corner of the Sidebar will provide a button for users to switch color schemes.
+
+    - **dark**  - Always show dark mode.
+    - **light** - Always show light mode.
+
 
 ##  Run Locally
 
@@ -122,7 +136,18 @@ $ bash tools/init.sh
 
 > Please note that the *Recent Update* list requires the latest git-log date of posts, thus make sure the changes in `_posts` have been committed before running this command.
 
-it will automatically generates the *Latest Modified Date* and *Categories / Tags* page for the posts.
+it will automatically generates the *Latest Modified Date* and *Categories / Tags* page for the posts and submit a commit. Its output is similar to the following log:
+
+```terminal
+[INFO] Success to update lastmod for 4 post(s).
+[INFO] Succeed! 3 category-pages created.
+[INFO] Succeed! 4 tag-pages created.
+[Automation] Updated the Categories, Tags, Lastmod for post(s).
+ 11 files changed, 46 insertions(+), 3 deletions(-)
+ ...
+Updated the Categories, Tags, Lastmod for post(s).
+```
+
 
 **3**. Push the changes to `origin/master` then go to GitHub website and enable GitHub Pages service for the repo.