[v1.3.x] docs/upgrade-sdk-version/v1.3.0.md: correct link to migration guide (#4516)

Signed-off-by: Eric Stroczynski <[email protected]>

Co-authored-by: Eric Stroczynski <[email protected]>

Author: openshift-cherrypick-robot

website/content/en/docs/upgrading-sdk-version/v1.3.0.md

@@ -21,7 +21,9 @@ _See [#4282](https://github.com/operator-framework/operator-sdk/pull/4282) for m
 
 ## Upgrade your Go project from "go.kubebuilder.io/v2" to "go.kubebuilder.io/v3"
 
-The newly released go/v3 plugin has many new features and (breaking) changes incompatible with projects created by go/v2. You are not required to upgrade and your go/v2 project will continue to work with new operator-sdk versions. If you wish to upgrade, check out the upstream [migration guide](https://master.book.kubebuilder.io/migration/plugin/plugins.html).
+The newly released go/v3 plugin has many new features and (breaking) changes incompatible with projects created by go/v2.
+You are not required to upgrade and your go/v2 project will continue to work with new operator-sdk versions.
+If you wish to upgrade, check out the upstream [migration guide](https://master.book.kubebuilder.io/migration/v2vsv3.html).
 
 Additionally, if using project version "3-alpha", you must update your `plugins` config field: