doc: Expand documentation for the cedit command

Add a little information about each subcommand.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/usage/cmd/cedit.rst b/doc/usage/cmd/cedit.rst
index 3d815bd..d34a220 100644
--- a/doc/usage/cmd/cedit.rst
+++ b/doc/usage/cmd/cedit.rst
@@ -24,6 +24,21 @@
 
 See :doc:`../../develop/cedit` for information about the configuration editor.
 
+cedit load
+~~~~~~~~~~
+
+Loads a configuration-editor description from a file. It creates a new cedit
+structure ready for use. Initially no settings are read, so default values are
+used for each object.
+
+cedit run
+~~~~~~~~~
+
+Runs the default configuration-editor event loop. This is very simple, just
+accepting character input and moving through the objects under user control.
+The implementation is at `cedit_run()`.
+
+
 Example
 -------