Grouse doesn't support Hugo themes which use GitInfo about grouse

[capnfabs]

Hey @shah! Thanks for filing the report about this, and for all the info you provided; it's very helpful.

So - the issue here is that:

• The Docsy theme uses Hugo's Git Info Variables to display modification timestamps / commit info for each page
• Grouse doesn't work with sites that use Hugo's Git Info Variables. Grouse copies Hugo source files to a temporary working directory and runs the build from there. This means that there isn't .git directory copied over, and so the system git used by hugo can't load any info (which is the source of the error message in the build step).

I was super unsure of the decision to roll my own checkout code when I released Grouse (I discuss it briefly here), and I think at some point in the next month, I'll re-work the code-checkout system to use git worktree instead, which should fix the Hugo GitInfo support as well.

In the meantime, I'll rename this issue accordingly and keep you updated here when I make the requisite changes.