simplify nullable declaration

docs/Kotlin.md

@@ -12,7 +12,7 @@
 | **Variable Declaration**     | `int age = 25;`                                                                                                           | `val age: Int = 25`                                                     | `let age: number = 25`                                                   |
 | **Immutable Variable**       | `final int age = 25;`                                                                                                     | `val age: Int = 25`                                                     | `const age: number = 25`                                                 |
 | **Type inference**           | `var age = 25;` (only for local variables)                                                                                | `val age = 25` (anywhere, also for return types)                        | `let age = 25` (anywhere, also for return types)                         |
-| **Nullable declaration**     | N/A (nulls allowed everywhere)                                                                                            | `var name: String? = null`                                          | `name?: string`                                                          |
+| **Nullable declaration**     | N/A (nulls allowed everywhere)                                                                                            | `name: String?`                                                         | `name?: string` (undefined)                                              |
 | **Nullable dereferencing**   | `Optional.ofNullable(person).map(p -> p.name).orElse(null)` (even more difficult with nested nullability)                 | `person?.name`                                                          | `person?.name`                                                           |
 | **Nullable fallback**        | `if (person.name != null) person.name; else "";`                                                                          | `person.name ?: ""`                                                     | `person.name ?? ''`                                                      |
 | **Function Declaration**     | `int add(int a, int b) { return a + b; }` (only inside of classes)                                                        | `fun add(a: Int, b: Int) = a + b`                                       | `function add(a: number, b: number) { return a + b }`                    |