Add 0.13.0 change log (#1941)

CHANGELOG.md

@@ -1,5 +1,25 @@
 # Changelog
 
+# 0.13.0
+
+## Features
+
+- **M3Query**: Federated queries (e.g. for cross region/zone queries) configurable to return a warning and partial results than a hard error to route around unhealthy regions (#1938)
+- **M3Query**: Add ability to turn on GRPC reflection for testing query endpoints using utilities like grpcurl (#1856)
+- **M3Query**: Add ability to use multiple config files for config overrides (#1934)
+- **M3DB**: Add ability to replicate writes best effort directly to multiple clusters by specifying multiple etcd clusters for M3DB client (#1859)
+- **M3Coordinator**: Add ability to replicate Prometheus remote write requests by forwarding the compressed body to downstream remote write endpoints (#1922, #1940)
+
+## Bug Fixes
+
+- **M3Coordinator**: Fix ability to delete coordinator placements (#1918)
+- **M3Aggregator**: Ensure flush manager worker pool is at least size 1 irregardless of num CPUs (#1881)
+
+## Documentation
+
+- **M3**: Add FAQ and seed with some frequently asked questions asking (#1927)
+- **M3Coordinator**: Fix the cluster placement endpoint documentation in the manual cluster setup instructions (#1936)
+
 # 0.12.0
 
 ## Features