bug: ASCII diagrams messing up vertical alignment

I noticed the [Docker page](https://learnxinyminutes.com/docker) has an ASCII diagram, but it shows all messed up in Chrome and Firefox:

The Markdown file seems to be correct though:

https://github.com/adambard/learnxinyminutes-docs/blob/449801eb7c3ee68e837eee512774bb304df446cf/docker.md?plain=1#L25-L35

I tried locally to change the `

` to triple backticks, but made no difference.

Open docker.md around lines 25-35 and compare the Markdown source with how the ASCII diagram renders on the Docker page. Reproduce the vertical-alignment problem in Chrome and Firefox, then verify that the diagram displays correctly in both browsers without changing its intended layout.

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