docs: add local image build section (#4449)

Signed-off-by: Charles-Edouard Brétéché <charled.breteche@gmail.com>

Signed-off-by: Charles-Edouard Brétéché <charled.breteche@gmail.com>

DEVELOPMENT.md

@@ -7,6 +7,9 @@ It contains instructions to build, run, and test Kyverno.
 - [Tools](#tools)
 - [Building and publishing an image locally](#building-and-publishing-an-image-locally)
 - [Building local binaries](#building-local-binaries)
+- [Building local images](#building-local-images)
+    - [Building local images with docker](#building-local-images-with-docker)
+    - [Building local images with ko](#building-local-images-with-ko)
 
 ## Tools
 
@@ -68,6 +71,91 @@ make build-cli
 
 The binary should be created at `./cmd/cli/kubectl-kyverno/kubectl-kyverno`.
 
+## Building local images
+
+In the same spirit as [building local binaries](#building-local-binaries), you can build local docker images instead of local binaries.
+
+Currently, we are supporting two build systems:
+- [Building local images with docker](#building-local-images-with-docker)
+- [Building local images with ko](#building-local-images-with-ko)
+
+> **Note**: We started with `docker` and are progressively moving to `ko`.
+
+As the `ko` based build system matures, we will deprecate and remove `docker` based builds.
+
+Choosing between `docker` and `ko` boils down to a prefix when invoking `make` targets. 
+For example:
+- `make docker-build-kyverno` creates a docker image using the `docker` build system
+- `make ko-build-kyverno` creates a docker image using the `ko` build system
+
+<!-- TODO: explain the way images are tagged. -->
+
+### Building local images with docker
+
+When building local images with docker you can specify the registry used to create the image names by setting the `REGISTRY` environment variable (default value is `ghcr.io`).
+
+> **Note**: You can build all local images at once by running `make docker-build-all`.
+
+#### Building kyvernopre image locally
+
+To build `kyvernopre` image on your local system, run:
+```console
+make docker-build-kyvernopre
+```
+
+The resulting image should be available locally, named `ghcr.io/kyverno/kyvernopre` (by default, if `REGISTRY` environment variable was not set).
+
+#### Building kyverno image locally
+
+To build `kyverno` image on your local system, run:
+```console
+make docker-build-kyverno
+```
+
+The resulting image should be available locally, named `ghcr.io/kyverno/kyverno` (by default, if `REGISTRY` environment variable was not set).
+
+#### Building cli image locally
+
+To build `cli` image on your local system, run:
+```console
+make docker-build-cli
+```
+
+The resulting image should be available locally, named `ghcr.io/kyverno/kyverno-cli` (by default, if `REGISTRY` environment variable was not set).
+
+### Building local images with ko
+
+When building local images with ko you can't specify the registry used to create the image names. It will always be `ko.local`.
+
+> **Note**: You can build all local images at once by running `make ko-build-all`.
+
+#### Building kyvernopre image locally
+
+To build `kyvernopre` image on your local system, run:
+```console
+make ko-build-kyvernopre
+```
+
+The resulting image should be available locally, named `ko.local/github.com/kyverno/kyverno/cmd/initcontainer`.
+
+#### Building kyverno image locally
+
+To build `kyverno` image on your local system, run:
+```console
+make ko-build-kyverno
+```
+
+The resulting image should be available locally, named `ko.local/github.com/kyverno/kyverno/cmd/kyverno`.
+
+#### Building cli image locally
+
+To build `cli` image on your local system, run:
+```console
+make ko-build-cli
+```
+
+The resulting image should be available locally, named `ko.local/github.com/kyverno/kyverno/cmd/cli/kubectl-kyverno`.
+
 ## Building and publishing an image locally
 
 First, make sure you [install `ko`](https://github.com/google/ko#install)