Update CHANGELOG with release notes. (#680)

CHANGELOG.md

@@ -2,13 +2,17 @@
 
 ## HEAD (Unreleased)
 
-- revert runtime requirement from node 16 to node 12
+**(None)**
+
+---
+
+## 3.18.1 (2022-07-07)
 
 - bug: Resolves a panic when using `comment-on-pr: true` when not running on an
   event of type `pull_request`.
   [#679](https://github.com/pulumi/actions/issues/679)
 
----
+- revert runtime requirement from node 16 to node 12
 
 ## 3.18.0 (2022-07-01)
 
@@ -118,17 +122,16 @@
 
 ## 3.0.0 (2021-04-19)
 
-- Upgrade to Pulumi 3.0
-  **PLEASE NOTE:** This minimum version of the Pulumi CLI to work with this
-  action has been updated to be 3.0.0. If this version requirement is not
-  satisfied then the action will throw an error
+- Upgrade to Pulumi 3.0 **PLEASE NOTE:** This minimum version of the Pulumi CLI
+  to work with this action has been updated to be 3.0.0. If this version
+  requirement is not satisfied then the action will throw an error
 
 ## 2.3.0 (2021-04-15)
 
 - Upgrade to v2.25.0 of Pulumi Automation API
-  [#180](https://github.com/pulumi/actions/pull/180)
-  **PLEASE NOTE:** This minimum version of the Pulumi CLI to work with this
-  action has been updated to be 2.25.0
+  [#180](https://github.com/pulumi/actions/pull/180) **PLEASE NOTE:** This
+  minimum version of the Pulumi CLI to work with this action has been updated to
+  be 2.25.0
 
 ## 2.2.0 (2021-03-22)