Update "Create and manage shares" doc

This is the basic user guide for manila:

- Update examples and outputs
- Add limits and metadata examples
- Add descriptions about common concepts
  including share type extra specifications
- Add contents for easy navigation

Change-Id: Idf374866a63e0da2c4af3157ac5f471af6173d5e
Closes-Bug: #1652375
Signed-off-by: Goutham Pacha Ravi <gouthampravi@gmail.com>

doc/source/user/share-network-operations.rst

@@ -4,6 +4,8 @@
 Create and manage share networks
 ================================
 
+.. contents:: :local:
+
 A share network stores network information to create and manage shares. A share
 network provides a way to designate a network to export shares upon. In the
 most common use case, you can create a share network with a private OpenStack
@@ -17,6 +19,11 @@ In either case, as long as the underlying network is connected to the clients
 (virtual machines, containers or bare metals), there will exist a direct path
 to communicate with shares exported on the share networks.
 
+.. important::
+
+   In order to use share networks, the share type you choose must have the
+   extra specification ``driver_handles_share_servers`` set to True.
+
 Create share networks
 ~~~~~~~~~~~~~~~~~~~~~
 

doc/source/user/share-network-subnet-operations.rst

@@ -4,6 +4,8 @@
 Create and manage share network subnets
 =======================================
 
+.. contents:: :local:
+
 A share network subnet stores network information to create and manage shares.
 To create and manage your share network subnets, you can use ``manila`` client
 commands. You can create multiple subnets in a share network, and if you do
@@ -12,6 +14,12 @@ considered default by the Shared File Systems service. The default subnet
 spans all availability zones. You cannot have more than one default subnet
 per share network.
 
+
+.. important::
+
+   In order to use share networks, the share type you choose must have the
+   extra specification ``driver_handles_share_servers`` set to True.
+
 Create a subnet in an existing share network
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~