750: Teach ad-hoc hooks line parsing

[guillaume-d]

Include some (partly regression) tests and a small doc.

[sds]

Thanks so much for opening this pull request, @guillaume-d. Very excited to move this forward.

Left a few comments to clarify how we could potentially make this experience a seamless one without having to introduce the concept of an "ad hoc" hook to the configuration format. Curious to get your perspective.

[sds]

Sincere apologies for the very slow response, @guillaume-d. Let me know your thoughts!

[guillaume-d]

Sincere apologies for the very slow response, @guillaume-d. Let me know your thoughts!

No problem, was started to worry something bad may have happened.
In the meantime, I have been implementing some kind of flattening, I will just finish it (hopefully today) and push that for now as a stepping stone, and once done will have another look at implementing your suggestions.

[guillaume-d]

Sincere apologies for the very slow response, @guillaume-d. Let me know your thoughts!

No problem, was started to worry something bad may have happened. In the meantime, I have been implementing some kind of flattening, I will just finish it (hopefully today) and push that for now as a stepping stone, and once done will have another look at implementing your suggestions.

Hi. I think all comments have finally been adressed now.

I am afraid I will not have much more time to do another review round (except maybe if feedback is very minor and comes fast, before I get sidetracked by other things).

If nothing comes I will just use my fork of overcommit going forward, and use #758 and future uses of this feature from there.