Extension methods section for IServiceCollection is overwhelming

### Describe the issue or suggestion

@sixpi was sharing their experience with me about trying to learn about DI and brought up the problem that IServiceCollection lists 456 extension methods: https://learn.microsoft.com/en-us/dotnet/api/microsoft.extensions.dependencyinjection.iservicecollection?view=net-8.0#extension-methods

This is way too much and can be overwhelming.

I think it the docs tooling was able to collapse extension methods that have a common name into a single entry it would help - this would reduce from 456 -> 156 entries. Also grouping by the type of the "this" parameter would also be helpful - this would show that there are only 76 method groups for `IServiceCollection` and the remaining are for `IEnumerable*/IList*`

cc @gewarren