update readme.

@@ -7,11 +7,13 @@ SRS is industrial-strength live streaming cluster, for the best conceptual integ
 
 Download from github.io: [Centos6-x86_64][centos0], [more...][more0]<br/>
 Download from ossrs.net: [Centos6-x86_64][centos1], [more...][more1]<br/>
-Website for SRS/2.0, read SRS 2.0 [Chinese][srs2_CN] or [English][srs2_EN].
+Website for SRS/3.0, read SRS 3.0 [Chinese][srs3_CN] or [English][srs3_EN].
 
 [![Donation](https://www.paypalobjects.com/webstatic/en_US/btn/btn_donate_92x26.png)][donation1]
 [![Paypal](https://www.paypalobjects.com/webstatic/en_US/btn/btn_donate_pp_142x27.png)][donation2]
 
+The below is `About`, `Usage`, `Product` and `Architecture` of SRS.
+
 ## About
 
 SRS(Simple RTMP Server) over state-threads created in 2013.10.
@@ -1279,4 +1281,6 @@ Winlin
 
 [srs2_CN]: https://github.com/simple-rtmp-server/srs/wiki/v2_CN_Home
 [srs2_EN]: https://github.com/simple-rtmp-server/srs/wiki/v2_EN_Home
+[srs3_CN]: https://github.com/simple-rtmp-server/srs/wiki/v3_CN_Home
+[srs3_EN]: https://github.com/simple-rtmp-server/srs/wiki/v3_EN_Home