Add a note that starting pserve with --daemon is no longer supported (#…

…196)

* Add a note that starting pserve with --daemon is no longer supported

For Pyramid 1.9 and newer, you cannot start Pyramid with pserve
--daemon.  This adds a note to the nginx deployment page to call
this out.

* Update PR of daemon deprecation with feedback

Update the PR to update starting pserve without the daemon command
and add links that daemonization was deprecated in Pyramid 1.6 and
removed in Pyramid 1.8

docs/deployment/nginx.rst

@@ -217,8 +217,15 @@ hosting the application under a different URL than ``/``.
 
 Running the pserve processes::
 
-    pserve --daemon --pid-file=pserve_5000.pid production.ini http_port=5000
-    pserve --daemon --pid-file=pserve_5001.pid production.ini http_port=5001
+    pserve production.ini http_port=5000
+    pserve production.ini http_port=5001
+
+.. note::
+
+   Daemonization of pserve was `deprecated in
+   Pyramid 1.6 <https://docs.pylonsproject.org/projects/pyramid/en/latest/whatsnew-1.6.html#deprecations>`_,
+   then `removed in Pyramid 1.8
+   <https://docs.pylonsproject.org/projects/pyramid/en/latest/whatsnew-1.8.html#backwards-incompatibilities>`_.
 
 Step 3: Serving Static Files with Nginx (Optional)
 ==================================================