update CHANGELOG.md

Author: nicholasgribanov

Diff for: CHANGELOG.md

@@ -6,7 +6,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased](https://github.com/open-telemetry/opentelemetry-python/compare/v1.7.0-0.26b0...HEAD)
-
+- `opentelemetry-instrumentation-tornado` Add support instrumentation for Tornado 5.1.1
+  ([#812](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/812))
+  
 ## [1.7.1-0.26b1](https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.7.0-0.26b0) - 2021-11-11
 
 - `opentelemetry-instrumentation-aws-lambda` Add instrumentation for AWS Lambda Service - pkg metadata files (Part 1/2)