Adding proposed overview sentence

Author: drewbatgit

hub/apps/develop/action-framework/action-json.md

@@ -47,7 +47,7 @@ Describes the format of the action definition JSON file format for Windows Copil
       {
         { 
           "type": "Uri", 
-          "uri": "contoso://greetUser? userName=${UserFriendlyName.Text}&petName=${PetName.Text}", 
+          "uri": "contoso://greetUser?userName=${UserFriendlyName.Text}&petName=${PetName.Text}", 
         }, 
         "where": [ 
           "${UserFriendlyName.Length > 3}" 

hub/apps/develop/action-framework/index.md

@@ -8,7 +8,7 @@ ms.localizationpriority: medium
 
 # Windows Copilot Runtime Actions providers
 
-TBD - Overview content
+Actions are atomic units of functionality that can be invoked by the Windows Copilot Runtime. Developers can register actions with the system by implementing an action provider app.
 
 
 ## Responsible AI Notes
@@ -20,5 +20,5 @@ When building AI backed actions, it is your responsibility as the Action author
 
 ## Related articles
 
-[Action definition JSON schema for Windows Copilot Runtime Actions providers](action-json.md)
-[Windows Copilot Runtime Actions provider package manifest XML format](action-provider-manifest.md)
+- [Action definition JSON schema for Windows Copilot Runtime Actions providers](action-json.md)
+- [Windows Copilot Runtime Actions provider package manifest XML format](action-provider-manifest.md)