docs: Cleanup migration guide

Signed-off-by: Dmitry Dygalo <dmitry@dygalo.dev>

MIGRATION.md

@@ -2,9 +2,7 @@
 
 ## Upgrading from 0.19.x to 0.20.0
 
-### New Features
-
-1. Draft-specific modules are now available:
+Draft-specific modules are now available:
 
    ```rust
    // Old (0.19.x)
@@ -20,7 +18,7 @@
 
    Available modules: `draft4`, `draft6`, `draft7`, `draft201909`, `draft202012`
 
-2. Use the new `options()` function for easier customization:
+Use the new `options()` function for easier customization:
 
    ```rust
    // Old (0.19.x)
@@ -30,8 +28,6 @@
    let options = jsonschema::options();
    ```
 
-### Deprecations and Renames
-
 The following items have been renamed. While the old names are still supported in 0.20.0 for backward compatibility, it's recommended to update to the new names:
 
 | Old Name (0.19.x) | New Name (0.20.0) |