Add usage hint for footnotes to README.

Signed-off-by: Thomas Hochstein <thh@inter.net>

diff --git a/README.md b/README.md
index 772cef6..85e327c 100644 (file)
--- a/README.md
+++ b/README.md
@@ -11,3 +11,5 @@ personal use here.
 to the format of the Wordpress plugin
 [footnotes](https://wordpress.org/plugins/footnotes/) and back.
 
+Usage: `footnotes --to mmd|wp [--file $inputfile]`
+