Expanded migration notes to include decorators

docs/guide/migrations/0-6.md

@@ -130,6 +130,13 @@ Modifiers have renamed their `revert` property to `invert` to match the terms us
 
 Lazy proxies now call the options function with the base object as the `this` argument and the first parameter. Features with `options` functions are expected to pass the base object as the `this` argument and first parameter as well. The `OptionsFunc` type has already been updated for this, so TS will complain if you skip this migration step.
 
+You'll also want to add support for decorators. You'll want to add the new parameter `...decorators: GenericDecorator[]`, and then call their functions:
+
+- Gather their persistent data _outside_ the layer proxy, like `const decoratedData = decorators.reduce((current, next) => Object.assign(current, next.getPersistentData?.()), {})`
+- At the beginning of the layer proxy, call each `preConstruct` that exists, e.g. `decorators.forEach(d => d.preConstruct?.(feature))`
+- At the end of the layer proxy, call each `postConstruct` that exists, e.g. `decorators.forEach(d => d.postConstruct?.(feature))`
+- Gather props by generating them like `const decoratedProps = decorators.reduce((current, next) => Object.assign(current, next.getGatheredProps?.(achievement)), {})` and destructure it in the `GatherProps` function
+
 ## Fixing visibility changes
 
 Visibility properties now work with booleans, which has several implications.