Typo in MSTEST0016 description

## Describe the bug
https://learn.microsoft.com/en-us/dotnet/core/testing/mstest-analyzers/mstest0016
```
Rule description
A test class should have at least one test method or be static and have methods that are attributed with [AssemblyInitialization] or [AssemblyCleanup].
```
States `AssemblyInitialization`, but it should be `AssemblyInitialize`.

## Additional context
MSTest 3.6.0