[Docs] "Applies to" documentation is unclear

[theletterf]

When reading the quick reference entry on the "Applies to" macro, something didn't quite add up:

1. The syntax example shows stack:.
2. The output label renders as Elastic stack.

I'm guessing there's a centralized dictionary that translates shorthand labels to the desired output, but neither the quick reference nor the full entry explain where those are maintained.

The only reference I found in the source is

docs-builder/src/Elastic.Markdown/Slices/Components/ApplicableToComponent.cshtml

Line 10 in 46fd268

@RenderProduct("Elastic Stack", appliesTo.Stack)