update doc

Author: gy2006

README.md

@@ -19,30 +19,35 @@
 
 ## What is flow.ci?
 
-flow.ci is an open-source CI/CD automation server that designed for reducing the complexity and increasing user experience. It supports high availability, multiple building environment, and scalability with dynamic agents.
+flow.ci is an open-source CI/CD automation server that designed for setting up a self-hosted CI/CD service with the easiest, fastest and most painless way. It supports high availability, multiple building environment, and scalability with dynamic agents.
 
 - __High Availability__
 
   flow.ci is designed to work in the cloud -- public, private, or hybrid, it could be deployed with multiple instances, the configuration/jobs data on the node may not be lost when the instance fails.
 
+
 - __High Performance__
 
-  - __scaling__: automatically scale agent either on K8s cluster or Linux host
+  - __scaling__: auto scaling agents either on K8s cluster or Linux host
   - __parallel__: job steps can be executed in parallel on multiple agents
   - __cache__: cache anything to speed up the build
 
+
 - __Zero Configuration__
 
   flow.ci tries to minimize the complexity of any configuration, the server could be started with three command lines. It also provides build templates of many programming languages, a job could be started just using it.
 
+
 - __Online Debugging__
 
   flow.ci supports the online TTY terminal so that you could find out the problems in the running job from runtime terminal.
 
+
 - __Flexible Plugins__
 
   Using plugins on flow.ci is quite simple, you just need type the plugin name in the step. Developing a plugin is also quite easy, you could use any language on your own plugin development.
 
+
 - __Flexible Runtime__
 
   Each step or step group can be run either on any docker images or native os.