docs: enumerate breaking changes for v0.18.0 in CHANGELOG.md

Signed-off-by: Shane Utt <[email protected]>

Author: shaneutt

gateway-api/CHANGELOG.md

@@ -1,9 +1,54 @@
 # Changelog
 
-## Next
+## 0.18.0
 
 Supports: Gateway API `v1.4.0`
 
+>[!IMPORTANT]
+Breaking change
+
+### Breaking Changes
+
+* Several types have changed names to accommodate new generator procedures, and an updated version of kopium. The primary changes are:
+
+#### Standard API Type Changes (Breaking)
+
+**Consolidated Types (moved to `common` module):**
+- `GRPCFilterType`, `HTTPFilterType`, `HeaderMatchType`, `RedirectStatusCode`, `RequestOperationType`, `RequestRedirectScheme` → Replaced with more specific enums like `GrpcRouteRulesBackendRefsFiltersType`, `HttpRouteRulesBackendRefsFiltersType`, etc.
+- `GatewayAddress` → `GatewayAddresses`, `GatewayStatusAddresses`
+- `HTTPHeader`, `Kind`, `ParentReference`, `RequestMirrorReference`, `HeaderMatch`, `HeaderModifier`, `ParentRouteStatus`, `RequestMirror`, `RequestRedirectPath` → Removed from common module and inlined into specific route types
+- `RouteStatus` → Removed from common module; now specific to each route type
+
+**GRPCRoute Type Renamings:**
+- `GRPCRouteSpec` → `GrpcRouteSpec`
+- `GRPCRouteRule` → `GrpcRouteRules`
+- `GRPCBackendReference` → `GrpcRouteRulesBackendRefs`
+- `GRPCRouteFilter` → `GrpcRouteRulesFilters`, `GrpcRouteRulesBackendRefsFilters`
+- `GRPCRouteMatch` → `GrpcRouteRulesMatches`
+- `GRPCMethodMatch` → `GrpcRouteRulesMatchesMethod`
+- Added granular types: `GrpcRouteRulesBackendRefsFiltersRequestHeaderModifier`, `GrpcRouteRulesFiltersRequestMirror`, etc.
+
+**HTTPRoute Type Renamings:**
+- `HTTPRouteSpec` → `HttpRouteSpec`
+- `HTTPRouteRule` → `HttpRouteRules`
+- `HTTPBackendReference` → `HttpRouteRulesBackendRefs`
+- `HTTPRouteBackendFilter` → `HttpRouteRulesBackendRefsFilters`
+- `HTTPRouteFilter` → `HttpRouteRulesFilters`
+- `RouteMatch` → `HttpRouteRulesMatches`
+- `HTTPMethodMatch` → `HttpRouteRulesMatchesMethod`
+- `PathMatch` → `HttpRouteRulesMatchesPath`
+- `HTTPRouteTimeout` → `HttpRouteRulesTimeouts`
+- `HTTPRouteUrlRewrite` → `HttpRouteRulesFiltersUrlRewrite`, `HttpRouteRulesBackendRefsFiltersUrlRewrite`
+- Added many granular filter types like `HttpRouteRulesBackendRefsFiltersRequestRedirect`, `HttpRouteRulesFiltersRequestHeaderModifier`, etc.
+
+**Gateway Type Changes:**
+- Added `GatewayClassStatusSupportedFeatures`
+- `GatewayAddress` split into `GatewayAddresses` and `GatewayStatusAddresses`
+
+**Common Module Changes:**
+- New common types: `HttpRouteParentRefs`, `HttpRouteRulesBackendRefsFiltersRequestHeaderModifierAdd`, `HttpRouteRulesBackendRefsFiltersRequestMirrorBackendRef`, `HttpRouteRulesBackendRefsFiltersRequestMirrorFraction`
+- Enums now use more specific naming: `HttpRouteRulesBackendRefsFiltersRequestRedirectPathType`, `HttpRouteRulesBackendRefsFiltersRequestRedirectScheme`, `HttpRouteRulesBackendRefsFiltersRequestRedirectStatusCode`, `HttpRouteRulesMatchesHeadersType`
+
 ### Changes
 
 * Updated to [kube](https://github.com/kube-rs/kube) `v2.0.1`