Mention related packages?

I'm the author of [SmallCombinatorics.jl](https://github.com/matthias314/SmallCombinatorics.jl). Some users of my package [have suggested](https://github.com/matthias314/SmallCombinatorics.jl/issues/1#issuecomment-3081493100) that you mention it somewhere, for example in your README file. Compared to your package, SmallCombinatorics.jl is quite restricted in scope. However, the functions it provides are usually much faster than their counterparts in Combinatorics.jl because they are based on the non-allocating container types from [SmallCollections.jl](https://github.com/matthias314/SmallCollections.jl). (The README for SmallCombinatorics.jl has some benchmarks.) I imagine that such speed-ups could be relevant for some users. Another package that users might be interested in and that you could mention is [Combinat.jl](https://juliahub.com/ui/Packages/General/Combinat).

What do you think?