feat: add CHANGELOG entry for addition of ResourceBuilder

Author: pitoniak32

opentelemetry-sdk/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## vNext
 
+- Add `ResourceBuilder` for an easy way to create new `Resource`s
 - **DEPRECATED**:
   - `trace::Config` methods are moving onto `TracerProvider` Builder to be consistent with other signals. See https://github.com/open-telemetry/opentelemetry-rust/pull/2303 for migration guide.
     `trace::Config` is scheduled to be removed from public API in `v0.28.0`.