[v17] docs: update db gui client (#49153)

* docs: update db gui client

* docs: remove Teleport version ref in db gui client

Co-authored-by: Paul Gottschling <paul.gottschling@goteleport.com>

* docs: include peer as join session mode in access role ref

---------

Co-authored-by: Paul Gottschling <paul.gottschling@goteleport.com>

docs/pages/connect-your-client/gui-clients.mdx

@@ -10,9 +10,20 @@ work with Teleport.
 
 ### Prerequisites
 
-(!docs/pages/includes/edition-prereqs-tabs.mdx!)
+- A running Teleport cluster. If you want to get started with Teleport, [sign
+  up](https://goteleport.com/signup) for a free trial or [set up a demo
+  environment](../admin-guides/deploy-a-cluster/linux-demo.mdx).
+
+- The `tsh` client tool. Visit [Installation](../installation.mdx) for instructions on downloading
+  `tsh`. See the [Using Teleport Connect](./teleport-connect.mdx) guide for a graphical desktop client
+  that includes `tsh`.
+
+- To check that you can connect to your Teleport cluster, sign in with `tsh login`. For example:
+
+  ```code
+  $ tsh login --proxy=<Var name="teleport.example.com" /> --user=<Var name="email@example.com" />
+  ```
 
-- (!docs/pages/includes/tctl.mdx!)
 - The Teleport Database Service configured to access a database. See one of our
   [guides](../enroll-resources/database-access/guides/guides.mdx) for how to set up the Teleport
   Database Service for your database.

docs/pages/includes/role-spec.mdx

@@ -397,7 +397,7 @@ spec:
           # generates a role name from the value capture
           roles: ['$1-admin']
 
-      # Teleport can attach annotations to pending Access Requests. these
+      # Teleport can attach annotations to pending Access Requests. These
       # annotations may be literals, or be variable interpolation expressions,
       # effectively creating a means for propagating selected claims from an
       # external identity provider to the plugin system.
@@ -435,7 +435,7 @@ spec:
         # The different session kinds this policy applies to.
         kinds: ['k8s', 'ssh']
         # The list of session participant modes the role may join the session as.
-        modes: ['moderator', 'observer']
+        modes: ['moderator', 'observer', 'peer']
 
     # spiffe is a list of SPIFFE IDs that the role holder is allowed to request
     # SVIDs for. As long as the request matches one of the blocks within the