Rename README.txt to README.md
diff --git a/Makefile.am b/Makefile.am
index 09b92ea..24e5e55 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -38,7 +38,7 @@
 EXTRA_DIST =                                                                 \
   autogen.sh                                                                 \
   generate_descriptor_proto.sh                                               \
-  README.txt                                                                 \
+  README.md                                                                  \
   INSTALL.txt                                                                \
   LICENSE                                                                    \
   CONTRIBUTORS.txt                                                           \