Add changelog for 2.0.0

CHANGELOG.md

+## 2.0.0 (2025-04-14)
+
+### Added (2 changes)
+
+- [Document example with external secrets integration](https://gitlab.com/components/opentofu/-/commit/244ed23cb7797a278d953ab0bab5e106b1c575cf) ([merge request](https://gitlab.com/components/opentofu/-/merge_requests/268))
+- [Document how to work with auto-encrypted states locally](https://gitlab.com/components/opentofu/-/commit/3a1b750c4611be7788aba9036c3119c3d935d8fe) ([merge request](https://gitlab.com/components/opentofu/-/merge_requests/267))
+
+### Changed (2 changes)
+
+- [Change default for `version` input to match component version](https://gitlab.com/components/opentofu/-/commit/9b69280a41644f127e47c812b64dd1426ff78eb9) ([merge request](https://gitlab.com/components/opentofu/-/merge_requests/266))
+- [Use GITLAB_TOFU_STATE_NAME for plan job resource_group value](https://gitlab.com/components/opentofu/-/commit/00f5ccbad78bd04aaa2d2a00e4fb668d7b5b435f) ([merge request](https://gitlab.com/components/opentofu/-/merge_requests/265))
+
 ## 2.0.0-rc1 (2025-04-10)
 
 ### Changed (2 changes)