Fix help text for fleet list command (#9114)

Author: dvadas

src/fleet/HISTORY.rst

@@ -146,3 +146,7 @@ Release History
 1.6.3
 ++++++
 * Mark gate commands as preview, fixing bug from version 1.6.0.
+
+1.6.4
+++++++
+* Fix help text for `fleet list` command.

src/fleet/azext_fleet/_help.py

@@ -53,11 +53,11 @@
 
 helps['fleet list'] = """
     type: command
-    short-summary: Lists all fleets within a resource group.
+    short-summary: Lists all fleets.
     examples:
-        - name: List all fleets with a specific subscription.
+        - name: List all fleets within your current subscription.
           text: az fleet list
-        - name: List all fleets that exist within a specific subscription and resource group.
+        - name: List all fleets that exist within your current subscription and the chosen resource group.
           text: az fleet list -g MyResourceGroup
 """