Update readme

README.md

@@ -19,7 +19,7 @@ Using the nanopb library
 To use the nanopb library, you need to do two things:
 
 1. Compile your .proto files for nanopb, using protoc.
-2. Include pb_encode.c and pb_decode.c in your project.
+2. Include pb_encode.c, pb_decode.c and pb_common.c in your project.
 
 The easiest way to get started is to study the project in "examples/simple".
 It contains a Makefile, which should work directly under most Linux systems.