Update changelog for 0.23.1. (#3629)

Author: sean-mcmanus

Extension/CHANGELOG.md

@@ -1,5 +1,12 @@
 # C/C++ for Visual Studio Code Change Log
 
+## Version 0.23.1: May 13, 2019
+### Bug Fixes
+* Fix `launch.json` creation when `intelliSenseEngine` is `"Disabled"`. [#3583](https://github.com/microsoft/vscode-cpptools/issues/3583)
+* Fix C/C++ commands not working if the language service isn't activated. [#3615](https://github.com/microsoft/vscode-cpptools/issues/3615)
+* Fix missing extension `"Details"` page. [#3621](https://github.com/microsoft/vscode-cpptools/issues/3621)
+* Fix some random crashes related to IntelliSense inactive region processing.
+
 ## Version 0.23.0: May 6, 2019
 ### New Features
 * Add a configuration UI editor to edit IntelliSense settings defined in the underlying `c_cpp_properties.json` file. [PR #3479](https://github.com/Microsoft/vscode-cpptools/pull/3479), [PR #3487](https://github.com/Microsoft/vscode-cpptools/pull/3487), [PR #3519](https://github.com/Microsoft/vscode-cpptools/pull/3519), [#3524](https://github.com/Microsoft/vscode-cpptools/issues/3524), [PR #3563](https://github.com/Microsoft/vscode-cpptools/pull/3563), [#3526](https://github.com/Microsoft/vscode-cpptools/issues/3526)