udpate readme

.gitignore

@@ -7,6 +7,3 @@ __pycache__/
 
 # pycharm files
 .idea/
-
-# some small demos
-demo/

README.md

@@ -1,27 +1,73 @@
-# About
+# NaHan: A Tiny Forum.
 
-A Forum(BBS) based on Flask.
+NaHan is a tiny forum written by Python flask and bootstrap.  Its goal is to learn flask and web development in practice.
 
+Topic page:
 
+![][1]
+
+Admin page:
+
+![][2]
 
 # Features
 
 Major features:
 
-1. Whole user manage system, contains registration, login, change password, retrieve;
-2. Users can create topics, append topics, have comments on topics.
-3. Send notifications when others @YOU in anywhere.
-4. Markdown supported, whether in topics or comments.
-5. A convenient administrator page, one can manage users, topics, nodes.
-6. A simple keyword search egine, one can search some specific topics.
+1. Whole user manage system, containing registration, login, password change, retrieve;
+2. Topic management system, login users can create topics, append topics, have comments on topics.
+3. Markdown support in topic, appendix of topic and comment.
+4. Can use `@someone` to remind other user anywhere.  The user which be is reminded will receive notify.
+5. A convenient administrator system, super user can block or activate users, topics, nodes and comments.
+6. A simple keyword search engine, one can search some specific topics.
 
 # How to Run
 
-1. Firstly, make sure all the relevant requirements installed.
-2. Do some configure in config.py.
+1. Firstly, make sure all the relevant modules installed.
+
+    You'd better use [virtualenv](https://virtualenv.pypa.io/en/stable/) to create a isolated python environments, and then use pip to install all the requirements.
+
+        pip install -r requirements.txt
+
+2. Do some custom configure in `config.py`, have a glance as followers:
+
+        # flask config
+        SECRET_KEY = os.environ.get('SECRET_KEY') or '!@#$%^&*12345678'
+        
+        # Config about senting email.
+        MAIL_SERVER = 'smtp.qq.com'
+        MAIL_PORT = 465
+        MAIL_USE_SSL = True
+        MAIL_USERNAME = os.environ.get('MAIL_USERNAME')
+        MAIL_PASSWORD = os.environ.get('MAIL_PASSWORD')
+        FORUM_MAIL_SUBJECT_PREFIX = 'NaHan'
+        FORUM_MAIL_SENDER = 'Nahan <selfboot@qq.com>'
 
+        # Optional, setting about translation.
+        BABEL_DEFAULT_LOCALE = 'zh'
+        BABEL_DEFAULT_TIMEZONE = 'CST'
+        
+        # Some config about forum, containing pagination page size, saving position and limit of avatar.
+        PER_PAGE = 10   
+        UPLOAD_FOLDER = os.path.join(basedir, 'nahan/static/upload')
+        ALLOWED_EXTENSIONS = set(['png', 'jpg', 'jpeg'])
+        MAX_CONTENT_LENGTH = 512 * 1024
+        
+        # Database setting.
+        SQLALCHEMY_DATABASE_URI = (os.environ.get('DEV_DATABASE_URL') or
+                               'mysql://root:******@localhost/nahan')
 
 3. Start corresponding database service.
-4. Change directory, run `python manage.py runserver`. 
+
+    In MacOS, start mysql using the following command:
+
+        mysql.server start
+
+4. Go to the project's directory, run `python manage.py runserver`. 
+
+For more about how to run a flask project, you need to have much knowledge about flask, [docs](http://flask.pocoo.org/docs/0.11/) can be found here. 
+
+[1]: picture/front_page.png
+[2]: picture/admin_page.png