More documentation
diff --git a/doc/intro.rst b/doc/intro.rst
index e27a7a2..cc89a19 100644
--- a/doc/intro.rst
+++ b/doc/intro.rst
@@ -14,6 +14,6 @@
 was no functionality for working with byte sequences (such as files)
 yet.
 
-.. TODO:: write more history
+.. todo:: write more history