Add the 'json' package. Code taken from simplejson 1.9 and contributed by Bob
Ippolito.

Closes issue #2750.
diff --git a/Doc/library/netdata.rst b/Doc/library/netdata.rst
index 1bf9b6d..9d4aa34 100644
--- a/Doc/library/netdata.rst
+++ b/Doc/library/netdata.rst
@@ -12,6 +12,7 @@
 .. toctree::
 
    email.rst
+   json.rst
    mailcap.rst
    mailbox.rst
    mhlib.rst