Updated Available C# and .NET features (markdown)

Available-C#-and-.NET-features.md

@@ -33,6 +33,7 @@ Feature | 🔵 `net48` | 🟢 `ns2.0` | convention for main BizHawk solution
 [`lock ((Lock) l)` sugar](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/statements/lock) | ⭕ | ⭕️ | should be able to use polyfill w/ C# 12
 [enhanced `params`](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/method-parameters#params-modifier) | ✔️ | ✔️️ | waiting for .NET 10 LTS
 ^ C# 13 ^ | 🔵 `net48` | 🟢 `ns2.0` | ---
+[`[UnsafeAccessor]`](https://learn.microsoft.com/en-us/dotnet/api/system.runtime.compilerservices.unsafeaccessorattribute) | ❌ | ❌ | unsupported
 [`[InlineArray]`](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/struct#inline-arrays) | ❌ | ❌ | unsupported
 [`using` aliases](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/using-directive#using-alias) for tuples, etc. | ✔️ | ✔️ | disallowed (use a struct instead of a tuple alias and we'll consider replacing them with `<Using/>` later)
 [default arguments for lambdas](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/lambda-expressions#input-parameters-of-a-lambda-expression) | ✔️ | ✔️ | discouraged (you should be using local methods)