add changelog entry

CHANGELOG.md

@@ -9,6 +9,8 @@ release.
 
 New:
 
+- Define resource mapping for Jaeger exporters
+  ([#891](https://github.com/open-telemetry/opentelemetry-specification/pull/891))
 - Add resource semantic conventions for operating systems
   ([#693](https://github.com/open-telemetry/opentelemetry-specification/pull/693))
 - Clarification of the behavior of the Trace API, re: context propagation, in
@@ -25,13 +27,13 @@ Updates:
   ([#690](https://github.com/open-telemetry/opentelemetry-specification/pull/690))
 - Remove lazy Event and Link API from Span interface
   ([#840](https://github.com/open-telemetry/opentelemetry-specification/pull/840))
-  * SIGs are recommended to remove any existing implementation of the lazy APIs
+  - SIGs are recommended to remove any existing implementation of the lazy APIs
     to avoid conflicts/breaking changes in case they will be reintroduced to the
     spec in future.
 - Provide clear definitions for readable and read/write span interfaces in the
   SDK
   ([#669](https://github.com/open-telemetry/opentelemetry-specification/pull/669))
-  * SpanProcessors must provide read/write access at least in OnStart.
+  - SpanProcessors must provide read/write access at least in OnStart.
 - Specify how `Probability` sampler is used with `ParentOrElse` sampler.
 - Clean up api-propagators.md, by extending documentation and removing redundant
   sections
@@ -73,8 +75,8 @@ Updates:
 - Clarify Tracer vs TracerProvider in tracing API and SDK spec.
   ([#619](https://github.com/open-telemetry/opentelemetry-specification/pull/619))
   Most importantly:
-  * Configuration should be stored not per Tracer but in the TracerProvider.
-  * Active spans are not per Tracer.
+  - Configuration should be stored not per Tracer but in the TracerProvider.
+  - Active spans are not per Tracer.
 - Do not set any value in Context upon failed extraction
   ([#671](https://github.com/open-telemetry/opentelemetry-specification/pull/671))
 - Clarify semantic conventions around span start and end time