.Net 8+ LINQ examples with EqualityComparer.Create

in .Net 8 new class was created to allow using lambdas anywhere that IQualityComparer is used. According to [https://github.com/dotnet/runtime/issues/101448](https://github.com/dotnet/runtime/issues/101448) the reasoning was that adding lambda functionality everywhere IEqualityComparer is used would become a maintenance headache.

Unfortunately, [EqualityComparer.Create](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.equalitycomparer-1.create) is very new and not well enough known to show up on google searches or otherwise be easily discoverable.

I propose adding small example snippets that demonstrate this new functionality so that it can be more easily discovered. For example: in [Enumerable.SequenceEqual(IEnumerable, IEnumerable, IEqualityComparer)](https://learn.microsoft.com/en-us/dotnet/api/system.linq.enumerable.sequenceequal?view=net-9.0#system-linq-enumerable-sequenceequal-1(system-collections-generic-ienumerable((-0))-system-collections-generic-ienumerable((-0))-system-collections-generic-iequalitycomparer((-0))))

The following example demonstrates how a lambda function can be used to compare to sequences:
```csharp
ProductA[] storeA = { new ProductA { Name = "apple", Code = 9 },
new ProductA { Name = "orange", Code = 4 } };

ProductA[] storeB = { new ProductA { Name = "apple", Code = 9 },
new ProductA { Name = "orange", Code = 4 } };

IEqualityComparer comparer = EqualityComparer.Create((first,second) => first.Code == second.Code);
bool equalAB = storeA.SequenceEqual(storeB, comparer);

Console.WriteLine("Equal? " + equalAB);

/*
This code produces the following output:

Equal? True
*/
```