Rename exercises dir

Name it instead "topics" so it won't be
strange if some topics included "exercises" directory.

topics/containers/solutions/working_with_images.md

@@ -0,0 +1,17 @@
+## Working with Images - Solution
+
+### Objective
+
+Learn how to work with containers images
+
+### Requirements
+
+Make sure Podman, Docker (or any other containers engine) is installed on your system
+
+### Instructions
+
+1. List the containers images in your environment - `podman image ls`
+2. Pull the latest ubuntu image - `podman image pull ubuntu:latest`
+3. Run a container with the image you just pulled  - `podman container run -it ubuntu:latest /bin/bash`
+4. Remove the image. Did it work? - No. There is a running container which is using the image we try to remove
+5. Do whatever is needed in order to remove the image - `podman rm <container_id>; podman image rm ubuntu`