Create new unreleased section in the changelog for 1.0.0 (#376)

CHANGELOG.md

@@ -2,7 +2,7 @@
 All notable changes to this project will be documented in this file based on the [Keep a Changelog](http://keepachangelog.com/) Standard. This project adheres to [Semantic Versioning](http://semver.org/).
 
 
-## Unreleased
+## [1.0.0](https://github.com/elastic/ecs/compare/v1.0.0-beta2...v1.0.0)
 
 ### Breaking changes
 
@@ -12,9 +12,9 @@ All notable changes to this project will be documented in this file based on the
 ### Bugfixes
 
 * Field set name "group" was being used as a leaf field at `user.group`, instead
- of being a nesting of the field set. This goes against a driving principle of ECS,
- and has been corrected. #308
-* Replaced incorrect examples in `cloud.provider`. #330
+  of being a nesting of the field set. This goes against a driving principle of ECS,
+  and has been corrected. #308
+* Replaced incorrect examples in `cloud.provider`. #330, #348
 * Changed the `url.port` type to `long`. #339
 
 ### Added
@@ -24,13 +24,12 @@ All notable changes to this project will be documented in this file based on the
 
 ### Improvements
 
-* Make phrasing of lowercasing directive more relevant, no matter where it's shown. #332
 * Clarified the definition of the host fields #325
 * Clarified the difference between `@timestamp` and `event.created`. #329
+* Make phrasing of lowercasing directive more relevant, no matter where it's shown. #332
 * Specify the `object_type` for field `labels`. #331
 * Loosen up definition of `geo` field set. Not necessarily geo-ip based, since `geo.name`. #333
-
-### Deprecated
+* Clarified guidelines on ID fields. #349
 
 ## [1.0.0-beta2](https://github.com/elastic/ecs/compare/v1.0.0-beta1...v1.0.0-beta2)