Allow nested describe blocks in DescribeSpec

[lwasyl]

In RSpec it's allowed to nest describe blocks. It's be nice to be able to nest describe blocks in DescribeSpec as well, but right now it's not possible. Is there any technical limitation to this or it's a deliberate decision?

I wanted to add a describe alias on DescribeScope, but the library describe is resolvable anyway and the tests fail in runtime

[LeoColman]

This is a deliberate decision, however I don't see any reason to not allow this.

Currently you can use

describe -> context -> context -> ... -> it

No real issue to disallow
describe -> describe -> ...

I'll add this.