docs: add notes distinguish from external plugin

docs/book/src/cronjob-tutorial/testdata/project/go.sum

@@ -25,7 +25,6 @@ github.com/evanphx/json-patch/v5 v5.6.0 h1:b91NhWfaz02IuVxO9faSllyAtNXHMPkC5J8sJ
 github.com/evanphx/json-patch/v5 v5.6.0/go.mod h1:G79N1coSVB93tBe7j6PhzjmR3/2VvlbKOFpnXhI9Bw4=
 github.com/fsnotify/fsnotify v1.6.0 h1:n+5WquG0fcWoWp6xPWfHdbskMCQaFnG6PfBrh1Ky4HY=
 github.com/fsnotify/fsnotify v1.6.0/go.mod h1:sl3t1tCWJFWoRz9R8WJCbQihKKwmorjAbSClcnxKAGw=
-github.com/go-logfmt/logfmt v0.5.1/go.mod h1:WYhtIu8zTZfxdn5+rREduYbwxfcBr/Vr6KEVveWlfTs=
 github.com/go-logr/logr v1.2.0/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
 github.com/go-logr/logr v1.2.4 h1:g01GSCwiDw2xSZfjJ2/T9M+S6pFdcNtFYsp+Y43HYDQ=
 github.com/go-logr/logr v1.2.4/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
@@ -80,10 +79,8 @@ github.com/imdario/mergo v0.3.6/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJ
 github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
 github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
-github.com/jpillora/backoff v1.0.0/go.mod h1:J/6gKK9jxlEcS3zixgDgUAsiuZ7yrSoa/FX5e0EB2j4=
 github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
 github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
-github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
 github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI2bnpBCr8=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
@@ -105,7 +102,6 @@ github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9G
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
-github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/onsi/ginkgo/v2 v2.9.5 h1:+6Hr4uxzP4XIUyAkg61dWBw8lb/gc4/X5luuxN/EC+Q=
 github.com/onsi/ginkgo/v2 v2.9.5/go.mod h1:tvAoo1QUJwNEU2ITftXTpR7R1RbCzoZUOs3RonqW57k=
 github.com/onsi/gomega v1.27.7 h1:fVih9JD6ogIiHUN6ePK7HJidyEDpWGVB5mzM7cWNXoU=

docs/book/src/plugins/creating-plugins.md

@@ -2,12 +2,34 @@
 
 [extending-cli]: extending-cli.md
 [controller-runtime]: https://github.com/kubernetes-sigs/controller-runtime
+[creating-external-plugins]: external-plugins.md
 [operator-pattern]: https://kubernetes.io/docs/concepts/extend-kubernetes/operator
 [sdk-ansible]: https://sdk.operatorframework.io/docs/building-operators/ansible/
 [sdk-cli-pkg]: https://pkg.go.dev/github.com/operator-framework/operator-sdk/internal/cmd/operator-sdk/cli
 [sdk-helm]: https://sdk.operatorframework.io/docs/building-operators/helm/
 [sdk]: https://github.com/operator-framework/operator-sdk
 
+<aside class="note warning">
+
+<h1>Note</h1>
+
+Extending Kubebuilder can be accomplished in two primary ways:
+
+`By re-using the existing plugins`: In this approach, you use Kubebuilder as a library.
+
+This enables you to import existing Kubebuilder plugins and extend them, leveraging their features to build upon.
+
+It is particularly useful if you want to add functionalities that are closely tied with the existing Kubebuilder features.
+
+
+`By Creating an External Plugin`: This method allows you to create an independent, standalone plugin as a binary.
+
+The plugin can be written in any language and should implement an execution pattern that Kubebuilder knows how to interact with.
+
+You can see [Creating external plugins][creating-external-plugins] for more info.
+
+</aside>
+
 ## Overview
 
 You can extend the Kubebuilder API to create your own plugins. If [extending the CLI][extending-cli], your plugin will be implemented in your project and registered to the CLI as has been done by the [SDK][sdk] project. See its [CLI code][sdk-cli-pkg] as an example.