Category or TestCategory

### Type of issue

Missing information

### Description

[Enter feedback here]
I'm using nUnit, and for historic (and probably mistaken) reasons we have many jobs that run `dotnet test --filter Category=MyCategory`, and not `dotnet test --filter TestCategory=MyCategory` (notice the use of `Category` vs `TestCategory`). Apparently it works well, but because it's not documented (nor here nor I found anywhere else any reference about it), I can't tell whether it's safe to continue using it or not. So please either document that `Category` and `TestCategory` can be used interchangeably when filtering nUnit, or describe the differences.

Thank you!

### Page URL

https://learn.microsoft.com/en-us/dotnet/core/testing/selective-unit-tests?pivots=nunit

### Content source URL

https://github.com/dotnet/docs/blob/main/docs/core/testing/selective-unit-tests.md

### Document Version Independent Id

e4443d71-7131-ae9b-447d-9ac0762a99fc

### Article author

@smadala

### Metadata

* ID: bb70526f-d02c-2b6c-3d34-0f4cac5809f0
* Service: **dotnet-fundamentals**