#38 port cmake material

[martinjrobins]

Fixes #38

[fcooper8472]

@martinjrobins I've started making a few changes, e.g. splitting the expected output from the commands themselves.

I also have a preference for the codeblocks being directly copyable, so I've removed some of the dir$ decoration... but before I go through the rest, happy to hear your thoughts on those changes.

Re output of code blocks, I want to revisit this work:
OxfordRSE/gutenberg#40
which would allow some decoration including (e.g.) that the code represents expected output, rather than input.

[martinjrobins]

yup, agree that code blocks should be copyable, so happy with this