Fix: Custom block editor link (WordPress#61962)

Co-authored-by: jorgefilipecosta <[email protected]>

packages/block-editor/README.md

@@ -66,7 +66,7 @@ registerCoreBlocks();
 
 Any components in this package that have a counterpart in [@wordpress/components](/packages/components/README.md) are an extension of those components.
 
-Unless you're [creating an editor](docs/how-to-guides/platform/custom-block-editor/README.md), it is recommended that the components in @wordpress/components should be used rather than the ones in this package as these components have been customized for use in an editor and may result in unexpected behaviour if used outside of this context.
+Unless you're [creating an editor](/docs/how-to-guides/platform/custom-block-editor.md), it is recommended that the components in @wordpress/components should be used rather than the ones in this package as these components have been customized for use in an editor and may result in unexpected behaviour if used outside of this context.
 
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