update docs

Author: madsodgaard

Sources/SwiftJavaDocumentation/Documentation.docc/SupportedFeatures.md

@@ -92,7 +92,7 @@ SwiftJava's `swift-java jextract` tool automates generating Java bindings from S
 | Non-escaping closures with primitive arguments/results: `func callMe(maybe: (Int) -> (Double))`   | ✅        | ✅   |
 | Non-escaping closures with object arguments/results: `func callMe(maybe: (JavaObj) -> (JavaObj))` | ❌        | ❌   |
 | `@escaping` closures: `func callMe(_: @escaping () -> ())`                                        | ❌        | ❌   |
-| Swift type extensions: `extension String { func uppercased() }`                      | 🟡       | 🟡  |
+| Swift type extensions: `extension String { func uppercased() }`                      | ✅       | ✅  |
 | Swift macros (maybe)                                                                 | ❌        | ❌   |
 | Result builders                                                                      | ❌        | ❌   |
 | Automatic Reference Counting of class types / lifetime safety                        | ✅        | ✅   |