* Improve Fixture support for Active Storage
Inspired by [76b33aa][], this commit extends the Active Storage
documentation to elaborate on how to declare fixtures.
In support of that, also introduce the `ActiveStorage::FixtureSet.blob`
method for injecting in-line [ActiveStorage::Blob][] attributes directly
into fixture YAML.
[76b33aa]: 76b33aa3d1
[ActiveStorage::Blob]: https://edgeapi.rubyonrails.org/classes/ActiveStorage/Blob.html
* Extra CR for style
* Two-space indention
* Explaining variable didn't explain, inline for style
Co-authored-by: David Heinemeier Hansson <david@loudthinking.com>
Sean Doyle