Background may need clarification

### 👓 What did you see?

According to the docs:

> You can only have one set of Background steps per Feature or Rule

https://cucumber.io/docs/gherkin/reference/#background

It's not clear to me whether:

a) Both feature and rule can have a background
b) Either feature or rule can have a background, but not both.

I think it's (a), but that sentence needs clarification.

### ✅ What did you expect to see?

Maybe something like this?

> A Feature can have only one set of Background steps. The same goes for a Rule. Both a Rule and its Feature may have a Background at the same time.

Start with the linked Gherkin Background documentation and review the sentence about one set of Background steps per Feature or Rule. Clarify whether both a Feature and its Rule may define Background steps, then update the wording so the allowed combinations are unambiguous.

Written by the indexing model from the issue text.