Comment 0 for bug 1351085

The only documentation I could find curtin is doc/topics/overview.rst
in the source. It has several problems:

 - It talks about a final_commands hook which doesn't exist AFAICS

 - It doesn't talk about the late_commands hook which definitely does
   exist

 - It refers to both TARGET_MOUNT_POINT and TARGET_MP; I suspect only
   one exists

 - It has confusing examples which I don't think work/make sense, e.g:

| config_hook: {{TARGET_MP}}/opt/curtin/config-hook

The documentation is also pretty sparse in many ways, it doesn't for
example:

 - Explain that the config is YAML

 - Explain other basic things about the config, e.g. what are the keys
   for hooks? Do the names matter? Does ordering matter?

 - Explain why you might want to use a list versus scalar for values

 - Explain how one might use YAML features such as 'repeated notes' to
   include data in the config that's intended for files

 - Explain that you probably want to use -- with curtin in-target to
   stop options of what you're trying to run being swallowed up by
   curtin