[core] update changelog for core-tracing release (#16413)

sdk/core/core-tracing/CHANGELOG.md

@@ -1,6 +1,6 @@
 # Release History
 
-## 1.0.0-preview.13 (Unreleased)
+## 1.0.0-preview.13 (2021-07-15)
 
 ### Features Added
 
@@ -10,13 +10,9 @@
 
 - Removed `TestTracer` and `TestSpan` from public API and into `@azure/test-utils`. [PR #16315](https://github.com/Azure/azure-sdk-for-js/pull/16315)
   - `TestTracer` and `TestSpan` are intended for test support when used by other Azure packages and not intended for use by end users.
-- Removed `setTracer`, @azure/core-tracing will now rely on the `trace` API to fetch a tracer from the global tracer provider.
+- Removed `setTracer`, @azure/core-tracing will now rely on the `trace` API to fetch a tracer from the global tracer provider. [PR #16347](https://github.com/Azure/azure-sdk-for-js/pull/16347)
   - If you are using `setTracer`, please use `trace.setGlobalTracerProvider(provider)` instead as described in the OpenTelemetry documentation.
-- Removed `NoOpTracer` and `NoOpSpan` from the public API. Please use `trace.wrapSpanContext(INVALID_SPAN_CONTEXT)` from `@opentelemetry/api` instead.
-
-### Key Bugs Fixed
-
-### Fixed
+- Removed `NoOpTracer` and `NoOpSpan` from the public API. Please use `trace.wrapSpanContext(INVALID_SPAN_CONTEXT)` from `@opentelemetry/api` instead. [PR #16315](https://github.com/Azure/azure-sdk-for-js/pull/16315)
 
 ## 1.0.0-preview.12 (2021-06-30)