Update broken links (#12660)

* Update broken links

There was 2 broken links. I changed same way with Data Module Reference page.

* Update docs/designers-developers/developers/block-api/README.md

Co-Authored-By: cagdasdag <cagdasdag81@gmail.com>

* Update docs/designers-developers/developers/block-api/README.md

Co-Authored-By: cagdasdag <cagdasdag81@gmail.com>

docs/designers-developers/developers/block-api/README.md

@@ -4,8 +4,8 @@ Blocks are the fundamental element of the Gutenberg editor. They are the primary
 
 ## Registering a block
 
-All blocks must be registered before they can be used in the editor. You can learn about block registration, and the available options, in the [block registration](block-api/block-registration.md) documentation.
+All blocks must be registered before they can be used in the editor. You can learn about block registration, and the available options, in the [block registration](../../../../docs/designers-developers/developers/block-api/block-registration.md) documentation.
 
 ## Block `edit` and `save`
 
-The `edit` and `save` functions define the editor interface with which a user would interact, and the markup to be serialized back when a post is saved. They are the heart of how a block operates, so they are [covered separately](block-api/block-edit-save.md).
+The `edit` and `save` functions define the editor interface with which a user would interact, and the markup to be serialized back when a post is saved. They are the heart of how a block operates, so they are [covered separately](../../../../docs/designers-developers/developers/block-api/block-edit-save.md).