Adds documentation for Javelin

I followed what's done for the cleanup.py script and re-used parts of
what was described in the javelin spec.

Change-Id: I57adc3764e75784d4614b6c03996433a4ee4332f
diff --git a/doc/source/index.rst b/doc/source/index.rst
index bc4fc46..1f06bc5 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -37,6 +37,7 @@
    :maxdepth: 1
 
    cleanup
+   javelin
 
 ==================
 Indices and tables