chore: add sigv4 to feed (#430)

Author: brandonskiser

feed.json

@@ -16,6 +16,10 @@
       "version": "1.12.5",
       "title": "Version 1.12.5",
       "changes": [
+        {
+          "type": "added",
+          "description": "(Experimental) Support for Sigv4 authentication with `q chat`. Launch chat with the environment variable `AMAZON_Q_SIGV4=1` - [#207](https://github.com/aws/amazon-q-developer-cli-autocomplete/pull/207)"
+        },
         {
           "type": "fixed",
           "description": "An issue with authentication failing for long chat sessions - [#424](https://github.com/aws/amazon-q-developer-cli-autocomplete/pull/424)"