Label specs with versions, and notice of new location (#6681)

Co-authored-by: Tracy Boehrer <[email protected]>

specs/botframework-activity/botframework-activity.md

@@ -1,5 +1,9 @@
 # Bot Framework -- Activity
 
+Version: 3.1.12
+
+**This specification has moved to [Agents SDK](https://github.com/microsoft/agents)**
+
 ## Abstract
 
 The Bot Framework Activity schema is an application-level representation of conversational actions made by humans and automated software. The schema includes provisions for communicating text, multimedia, and non-content actions like social interactions and typing indicators.

specs/botframework-activity/botframework-cards.md

@@ -1,5 +1,9 @@
 # Bot Framework -- Cards
 
+Version: 3.1.12
+
+**This specification has moved to [Agents SDK](https://github.com/microsoft/agents)**
+
 ## Abstract
 
 The Bot Framework Card schema is an application-level representation of interactive cards for use within chat and other applications. The schema includes provisions for controlling the content, layout, and interactive elements of a card.

specs/botframework-protocol/channel-update-spec.md

@@ -1,4 +1,7 @@
 # Updating the botframework-channel swagger file
+Version: 3.1.12
+
+**This specification has moved to [Agents SDK](https://github.com/microsoft/agents)**
 
 ## Abstract
 This document describe specific guidelines for updating the [swagger definition file](https://github.com/microsoft/botframework-sdk/blob/master/specs/botframework-protocol/botframework-channel.json) hosted in this repo. These guidelines specify the steps and requirements to maintaining a consistent source of truth that describes the state of connector-features in each SDK codebase. This source of truth is the combination of 2 concepts: