Cm Subscriptions Docs

- Included documentation for an overview of Cm Data Subscription for the
  Create and Delete use case.
- Only included the json schemas for the events that are coming in and
  going out of NCMP.
- Not mentioning anything abt the internal events we use between DMIs.
- The docs can later be used to explain abt the notifications when they
  are implemented.

Issue-ID: CPS-2324
Change-Id: I2497656e0e56c93054b7e92b1742a668463c3ffc
Signed-off-by: mpriyank <priyank.maheshwari@est.tech>
diff --git a/docs/cps-events.rst b/docs/cps-events.rst
index 25a253b..47aa73f 100644
--- a/docs/cps-events.rst
+++ b/docs/cps-events.rst
@@ -13,6 +13,7 @@
 
    cm-handle-lcm-events.rst
    data-operation-events.rst
+   cm-notification-subscriptions.rst
 
 .. note::
     Legacy async response on a client supplied topic for single cm handle data request are no longer supported. Click link below for the legacy specification.