docs: add more v7 breaking change info to migration docs

Author: hperrin

MIGRATING.md

@@ -6,7 +6,9 @@ This doc contains information that will help you migrate your code from an older
 
 ## Breaking Changes
 
-- The `@smui/common/elements` components are gone. It is replaced with the `Element` component exported from `@smui/common`. It takes a `tag` prop and creates an element dynamically with that tag name.
+- The `@smui/common/elements` components are gone. They are replaced with the `SmuiElement` component exported from `@smui/common`. It takes a `tag` prop and creates an element dynamically with that tag name. There's also a `Svg` component exported from `@smui/common` if you need an svg.
+- The "\*ComponentDev" types (like `MenuComponentDev`) are gone. You can now use the component as its type. Components that can take a `component` or `tag` prop (like `Button`) have required generic arguments that you can get around by using "InstanceType", like `let button: InstanceType<typeof Button>;`.
+- If you're using `classAdderBuilder`, you need to use `keyof SmuiElementMap` instead of `string` as its generic argument.
 
 # SMUI 5 -> SMUI 6
 

README.md

@@ -34,6 +34,8 @@ If you need help using SMUI, join the [Discord server](https://discord.gg/aFzmkr
 
 Upgrading from an old version? Be sure to read the [migration doc](MIGRATING.md).
 
+Upgrading from v6? No more elemental components; you can now use the "tag" prop for HTML elements or the "Svg" component. No more "ComponentDev" types; components can now be used as their type. Check out the [upgrade instructions](MIGRATING.md#smui-6---smui-7).
+
 Upgrading from v5? If you're still using the advanced styling method, it's really time to switch to the easy styling method. '/styled' endpoints are no longer provided. Check out the [upgrade instructions](MIGRATING.md#smui-5---smui-6).
 
 Upgrading from v4? SMUI v5 requires the [TypeScript preprocessor](https://github.com/sveltejs/svelte-preprocess). SMUI v6 does not though, so if you upgrade straight to v6, don't worry. Check out the [upgrade instructions](MIGRATING.md#smui-4---smui-5).
@@ -46,6 +48,7 @@ Upgrading from v2? There are **lots** of changes listed in the [upgrade instruct
 
 You can find older versions of the docs on their respective branch:
 
+- [v6 docs](https://github.com/hperrin/svelte-material-ui/tree/v6#readme)
 - [v5 docs](https://github.com/hperrin/svelte-material-ui/tree/v5#readme)
 - [v4 docs](https://github.com/hperrin/svelte-material-ui/tree/v4#readme)