DOCS fmt

[mattclegg]

Improve readability of docs

[jradtilbrook]

Thanks for this @mattclegg 👍
I didn't think there was any kind of standard for terraform but this made me actually go looking. And I found https://developer.hashicorp.com/terraform/language/syntax/style which says 2 spaces.

Can you update https://github.com/buildkite/terraform-provider-buildkite/blob/main/.editorconfig#LL15C19-L15C19 to add in .tf files as well and then I think we can merge this

[mcncl]

I've approved these changes and the tests have passed, I'll also merge it in.

@mattclegg, given this is an aesthetic/readability change, it'll be included in the next release rather than triggering a new one for it.