docs: update the v2 migration guide (#2231)

Author: tatomyr

README.md

@@ -11,6 +11,11 @@ Supports OpenAPI 3.1, 3.0 and OpenAPI 2.0 (legacy Swagger), AsyncAPI 3.0 and 2.6
 
 ![OpenAPI CLI toolset](./media/redocly-cli.gif)
 
+## Migration
+
+Migrating from Redocly CLI v1 to v2?
+Here's the [guide](https://redocly.com/docs/cli/guides/migrate-to-v2) to make the transition smoother.
+
 ## Usage
 
 ### Node

docs/@v2/guides/migrate-to-v2.md

@@ -16,6 +16,10 @@ This affects [plugins](../configuration/reference/plugins.md): update your plugi
 
 ### Configuration changes
 
+The only default configuration file name is now `redocly.yaml`.
+If you still use the legacy `.redocly.yaml`, please rename it.
+You can still use a different file name, but you must explicitly specify it with the `--config` flag.
+
 Several deprecated configuration options have been removed:
 
 ```yaml
@@ -120,11 +124,6 @@ rules:
 - **Commands**: The `preview-docs` command has been removed - use `preview` instead.
 - **Labels**: The `labels` field in the `apis` section has been removed.
 
-### Config file name
-
-The only default configuration file name is now `redocly.yaml`.
-You can still use a different file name, but you must explicitly specify it with the `--config` flag.
-
 ## New features
 
 ### Spec ruleset