♻️ Update instructions about lab environments

The link to Play With Docker was broken. Also, since PWD was
out of capacity, I also added a link to KodeKloud.

slides/containers/Training_Environment.md

@@ -15,11 +15,21 @@ class: title
 
 - If you are doing or re-doing this course on your own, you can:
 
-  - install Docker locally (as explained in the chapter "Installing Docker")
+  - install [Docker Desktop][docker-desktop] or [Podman Desktop][podman-desktop]
+    <br/>(available for Linux, Mac, Windows; provides a nice GUI)
 
-  - install Docker on e.g. a cloud VM
+  - install [Docker CE][docker-ce] or [Podman][podman]
+    <br/>(for intermediate/advanced users who prefer the CLI)
 
-  - use https://www.play-with-docker.com/ to instantly get a training environment
+  - try platforms like [Play With Docker][pwd] or [KodeKloud]
+    <br/>(if you can't/won't install anything locally)
+
+[docker-desktop]: https://docs.docker.com/desktop/
+[podman-desktop]: https://podman-desktop.io/downloads
+[docker-ce]: https://docs.docker.com/engine/install/
+[podman]: https://podman.io/docs/installation#installing-on-linux
+[pwd]: https://labs.play-with-docker.com/
+[KodeKloud]: https://kodekloud.com/free-labs/docker/
 
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