The bulk of the text on this page hasn't been revised for some time and
so parts of it were using non-idiomatic terminology or not defining terms
at all.
The main goal of this revision is to standardize on the following terms:
- "provider configuration" refers to a specific provider block in config,
as a distinct idea from the provider _itself_, which is a singleton.
- "Default" vs. "additional" provider configurations, distinguishing
those without and with "alias" arguments respectively. These are named
here so that we can use this terminology to describe the different
behaviors of each for the purposes of provider inheritance between
modules.