message: Add package rename to breaking.md
diff: ## 0.19 Breaking Changes
  - [Container's "error" event](#Container-Error-Event)
  - [IUrlResolver change from requestUrl to getAbsoluteUrl](#IUrlResolver-change-from-requestUrl-to-getAbsoluteUrl)
  +- [Package rename from `@microsoft/fluid-*` to `@fluidframework/*`](#package-rename)
  +
  +### Package rename
  +Package with the prefix "@microsoft/fluid-" is renamed to "@fluidframework/" to take advanage a separate namespace for fluid framework SDK packages.
  ### Container Error Event
  "error" event is gone. All critical errors are raised on "closed" event via optiona error object.
  