docs(install.adoc) Add podman guide

docs/modules/setup/pages/install.adoc

@@ -16,6 +16,8 @@
 :uri-docker-get-started: https://docs.docker.com/get-started/
 :uri-docker-compose-install: https://docs.docker.com/compose/install/
 :uri-docker-container-networking: https://docs.docker.com/config/containers/container-networking/
+:uri-podman-get-started: https://podman.io/getting-started/
+:uri-podman-compose-install: https://github.com/containers/podman-compose
 :uri-k8s-publish-service: https://kubernetes.io/docs/concepts/services-networking/service/#publishing-services-service-types
 :uri-k8s-definition-files: https://raw.githubusercontent.com/yuzutech/kroki/master/docs/modules/setup/examples/k8s
 
@@ -24,24 +26,25 @@ you first need to install the gateway server.
 
 [TIP]
 ====
-We recommend installing Kroki using *Docker*, especially if you don't want to manually install diagrams libraries.
+We recommend installing Kroki using containers with either *Docker* or *Podman*, especially if you don't want to manually install diagrams libraries.
 
 However, you can also install each diagrams libraries that you want to use and run the gateway server as a _standalone executable jar_.
 Consult the xref:manual-install.adoc[manual install page] to find out how.
 ====
 
-Assumptions:
-
-* [x] {uri-docker-get-started}[Docker] is installed on your machine.
-* [x] {uri-docker-compose-install}[Docker Compose] is installed on your machine (optional).
-
 On this page, you'll learn:
 
 * [x] How to run Kroki
 * [x] How to configure Kroki
 
 == Using Docker
 
+Assumptions:
+
+* [x] {uri-docker-get-started}[Docker] is installed on your machine.
+
+To start the Kroki gateway server, run the command:
+
 [source,docker-cli]
 docker run yuzutech/kroki
 
@@ -64,7 +67,14 @@ docker run -p8080:8000 -d yuzutech/kroki
 == Using docker-compose
 
 You can use `docker-compose` to run multiple containers.
-Here's an example where we start all the containers:
+
+Assumptions:
+
+* [x] {uri-podman-get-started}[Podman] is installed on your machine.
+* [x] {uri-podman-compose-install}[Podman-compose] is installed on your machine.
+
+Here's an example where we start all the containers.
+In this example host port 8000 is exposed.
 
 .docker-compose.yml
 [source,yml]
@@ -75,6 +85,44 @@ include::example$kroki-docker-compose.yml[]
 [source,docker-cli]
 docker-compose up -d
 
+== Using Podman
+
+Podman is a drop-in replacement for Docker for Linux systems only, and is available for many distributions.
+It is light-weight, does not need a daemon running in the background, and is built with container security in mind.
+
+Using Podman is a useful learning, development and testing step for running pods of containers in your linux environment.
+It is also a useful intermediate step if you are looking to lift your Kroki implementation into a Kubernetes environment.
+
+Assumptions:
+
+* [x] {uri-docker-get-started}[Docker] is installed on your machine.
+
+To start the Kroki gateway server using `podman`, run the command:
+
+[source,docker-cli]
+podman run yuzutech/kroki
+
+NOTE: The only difference is using `podman` instead of `docker`.
+
+
+== Using podman-compose
+
+To start a set of containers together in the same pod, use `podman-compose`.
+It is a helper program for podman with the same purpose as `docker-compose` except that it runs containers without a daemon and in certain configurations is able to run as a normal user instead of root.
+
+Using podman-compose does not require installing the docker-compose application.
+
+NOTE: This is different to the latest release of Podman v3, which requires `docker-compose` be installed.
+
+Assumptions:
+
+* [x] {uri-podman-get-started}[Podman] is installed on your machine.
+* [x] {uri-podman-compose-install}[Podman-compose] is installed on your machine.
+
+To use the the same docker-compose.yml file as in <<using-docker-compose>> and bring up your pod, run the command:
+
+[source,docker-cli]
+podman-compose up -d
 
 === Images