README: Add wiki link

Author: frostyplanet

README.md

@@ -16,6 +16,8 @@ High-performance spsc/mpsc/mpmc channels.
 It supports async context, or communicates between async-blocking context.
 
 Implemented with lockless in mind, low level is based on crossbeam-channel.
+For the concept, please refer to [wiki](https://github.com/frostyplanet/crossfire-rs/wiki).
+
 
 ## Stability and versions
 

src/lib.rs

@@ -5,6 +5,7 @@
 //! It supports async context, and bridge the gap between async and blocking context.
 //!
 //! Implemented with lockless in mind, low level is based on crossbeam-channel.
+//! For the concept, please refer to [wiki](https://github.com/frostyplanet/crossfire-rs/wiki).
 //!
 //! ## Stability and versions
 //!