spelling fix

Author: j-f1

Sources/JavaScriptKit/BasicObjects/JSPromise.swift

@@ -66,7 +66,7 @@ public final class JSPromise: JSBridgedClass {
         self.init(unsafelyWrapping: Self.constructor.reject!(reason).object!)
     }
 
-    /// Schedules the `success` closure to be invoked on sucessful completion of `self`.
+    /// Schedules the `success` closure to be invoked on successful completion of `self`.
     @discardableResult
     public func then(success: @escaping (JSValue) -> ConvertibleToJSValue) -> JSPromise {
         let closure = JSOneshotClosure {
@@ -75,7 +75,7 @@ public final class JSPromise: JSBridgedClass {
         return JSPromise(unsafelyWrapping: jsObject.then!(closure).object!)
     }
 
-    /// Schedules the `success` closure to be invoked on sucessful completion of `self`.
+    /// Schedules the `success` closure to be invoked on successful completion of `self`.
     @discardableResult
     public func then(success: @escaping (JSValue) -> ConvertibleToJSValue,
                      failure: @escaping (JSValue) -> ConvertibleToJSValue) -> JSPromise {