add ccache and dot to README

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/README b/README
index de3585a..b2412fc 100644 (file)
--- a/README
+++ b/README
@@ -17,6 +17,10 @@ Requirement:
        
        * gcc           http://gcc.gnu.org/
 
+Optionals tools:
+
+       * ccache        http://ccache.samba.org/        to improve recompilation
+       * dot           http://www.graphviz.org/        to enable graphes with the nitdoc tool
 
 Important files and directory: