docs: add release notes for v0.19.0 (#1525)

* docs: add release notes for v0.19.0

* edit release notes & prep (#1527)

---------

Co-authored-by: Miyoung Choi <miyoungc@nvidia.com>

Author: Pouyanpi

docs/project.json

@@ -1 +1 @@
-{ "name": "nemo-guardrails-toolkit", "version": "0.18.0" }
+{ "name": "nemo-guardrails-toolkit", "version": "0.19.0" }

docs/release-notes.md

@@ -14,6 +14,25 @@ For a complete record of changes in a release, refer to the
 
 ---
 
+(v0-19-0)=
+
+## 0.19.0
+
+(v0-19-0-features)=
+
+### Key Features
+
+- Added support for LangChain 1.x, including the content blocks API for reasoning traces and tool calls.
+
+(v0-19-0-fixed-issues)=
+
+### Fixed Issues
+
+- Fixed TypeError in Colang 2.x chat caused by incorrect type conversion between `State` and `dict`.
+- Fixed async streaming support for the ChatNVIDIA provider patch by adding a new `async_stream_decorator`.
+
+---
+
 (v0-18-0)=
 
 ## 0.18.0

docs/versions1.json

@@ -1,6 +1,10 @@
 [
     {
         "preferred": true,
+        "version": "0.19.0",
+        "url": "../0.19.0/"
+    },
+    {
         "version": "0.18.0",
         "url": "../0.18.0/"
     },