Minor changes to fork guidance following mongoid (#1006)

Author: p-mongo

source/tutorials/ruby-driver-create-client.txt

@@ -572,8 +572,8 @@ When ``#close`` is called on a client by any thread, all connections are closed:
     client.close
 
 
-Use with Forking Servers
-------------------------
+Usage with Forking Servers
+--------------------------
 
 When using the Mongo Ruby driver with a forking web server such as Unicorn,
 worker processes should generally each have their own Mongo::Client instances.
@@ -584,7 +584,7 @@ This is because:
 2. File descriptors like network sockets are shared between parent and
    child processes.
 
-It is easiest to not create any Mongo::Client instances prior to the fork.
+It is recommended to not create any Mongo::Client instances prior to the fork.
 If the parent process needs to perform operations on the MongoDB database,
 reset the client in an ``after_fork`` handler which is defined in
 ``unicorn.rb``:
@@ -616,6 +616,11 @@ the following code will close the connection in the parent:
 *Note:* This pattern should be used with Ruby driver version 2.6.2 or higher.
 Previous driver versions did not recreate monitoring threads when reconnecting.
 
+*Note:* If the parent process performs operations on the Mongo client and
+does not close it, the parent process will continue consuming a connection slot
+in the cluster and will continue monitoring the cluster for as long as the
+parent remains alive.
+
 Details on Retryable Writes
 ---------------------------