Replace `bash` markdown code blocks with `console`

[linusg]

At least on GitHub, bash renders the root shell lines as comments - console is more appropriate here. See https://stackoverflow.com/a/49004070.

Example:

[jpmens]

I had noticed the comments but wasn't sure whether the result was actually quite nice. Anyhow, I've now learned about console, thank you.

[jpmens]

Merged, merci!