update doc

README.md

@@ -1,10 +1,21 @@
 R3
 ================
 
-R3 is an URI router library. It compiles your route paths into a prefix trie.
-By using the constructed prefix trie in the start-up time, so you can dispatch 
+R3 is an URI router library with high performance, thus, it's implemented in C.
+It compiles your route paths into a prefix trie.
+
+By using the constructed prefix trie in the start-up time, you can dispatch
 routes with efficiency.
 
+
+Requirement
+-----------------------
+
+* cmake
+* check
+* pcre
+* jemalloc
+
 Pattern Syntax
 -----------------------
 
@@ -96,3 +107,10 @@ if ( $error ) {
 }
 ```
 
+Hacking
+----------------------
+
+    cmake CMakeLists.txt
+    make
+
+