diff --git a/borderify/README.md b/borderify/README.md
new file mode 100644
index 0000000..ea3b498
--- /dev/null
+++ b/borderify/README.md
@@ -0,0 +1,14 @@
+# borderify
+
+## What it does
+
+This extension just includes:
+
+* a content script, "borderify.js", that is injected into any pages
+under "mozilla.org/" or any of its subdomains
+
+The content script draws a border around the document.body.
+
+## What it shows
+
+* how to inject content scripts declaratively using manifest.json