Document interface member visibility logic

Signed-off-by: Graham <gpe@openrs2.dev>

deob/src/main/java/dev/openrs2/deob/transform/VisibilityTransformer.kt

@@ -60,6 +60,7 @@ class VisibilityTransformer : Transformer() {
         access: Int
     ): Int {
         if (classAccess and Opcodes.ACC_INTERFACE != 0) {
+            // interface members are always public
             return Opcodes.ACC_PUBLIC
         }