Generate proper header dependency graph with Jmk2
diff --git a/doc/jmk.rst b/doc/jmk.rst
index 224abc8..e97efca 100644
--- a/doc/jmk.rst
+++ b/doc/jmk.rst
@@ -11,7 +11,9 @@
The script ``bin/jmk2`` looks in the source tree for ``Jmk2`` files,
and process each one into the corresponding Makefile. It accepts
option definitions with the ``-D`` flag, eg ``./bin/jmk2
--DSOME_OPTION=123``.
+-DSOME_OPTION=123``. You can also specify the C compiler, assembler,
+and linker to use with the ``-c``, ``-a``, and ``-l`` flags,
+respectively.
Here is an example Jmk2 file: