website: Reconcile docs about plugin discovery and downloading
I'm attempting to keep things simple for normal users while making sure we've
got the full behavior written down somewhere for plugin developers.
This commit doesn't stand alone; it's paired with a commit in the
terraform-website repo, to deal with some related content in the "extend"
section.
The docs did not mention that it is possible to provide overrides for specific
plugins by placing them into a `terraform.d/plugins/os_arch/` directory inside
the working dir.
Closes#15727.
This restores the earlier behavior of the first positional argument to
terraform init in 0.9, but as a command line option.
The positional argument was removed to improve consistency with other
commands that take a working directory as their first positional argument.
It was originally intended that this functionality would return in a
later release along with some other general improvements to Terraform's
module handling, but we're introducing here an interim solution that
uses the existing module source concept, to allow for easier porting of
workflows that previously depended on the automatic copy behavior.
In a future release this feature may change again as the module
improvements design firms up, but we expect it to be broadly compatible
with this temporary state.
The "terraform init" command has a lot of different functionality now,
making it hard to follow all of the options in the previous presentation.
Instead, here we describe each of the steps and its associated options
separately, hopefully making it easier to understand what each option
relates to.
In addition, much of the detail around backend partial configuration is
factored out into the backend configuration page, where it seems more
"at home"; previously it felt hard to follow exactly how partial
configuration would be used, due to the information on it being split over
two different pages.
Nick Fagerlund