fix: Enum name changes

Author: JacquesDIconica

lib/src/config/introduction.dart

@@ -22,8 +22,8 @@ enum IntroductionDisplayMode {
 }
 
 enum IntroductionControlMode {
-  twoButton,
-  oneButton,
+  previousNextButton,
+  singleButton,
 }
 
 enum IntroductionButtonType {
@@ -111,8 +111,8 @@ class IntroductionOptions {
   final IntroductionDisplayMode displayMode;
 
   /// When [IntroductionDisplayMode.multiPageHorizontal] is selected multiple controlMode can be selected.
-  /// [IntroductionControlMode.twoButton] shows two buttons at the bottom of the screen to return or proceed. The skip button is placed at the top left of the screen.
-  /// [IntroductionControlMode.oneButton] contains one button at the bottom of the screen to proceed. Underneath is clickable text to skip if the current page is the first page. If the current page is any different it return to the previous screen.
+  /// [IntroductionControlMode.previousNextButton] shows two buttons at the bottom of the screen to return or proceed. The skip button is placed at the top left of the screen.
+  /// [IntroductionControlMode.singleButton] contains one button at the bottom of the screen to proceed. Underneath is clickable text to skip if the current page is the first page. If the current page is any different it return to the previous screen.
   ///
   final IntroductionControlMode controlMode;
 
@@ -145,7 +145,7 @@ class IntroductionOptions {
     this.displayMode = IntroductionDisplayMode.multiPageHorizontal,
     this.skippable = false,
     this.buttonBuilder,
-    this.controlMode = IntroductionControlMode.twoButton,
+    this.controlMode = IntroductionControlMode.previousNextButton,
   }) : assert(
           !(identical(indicatorMode, IndicatorMode.custom) &&
               indicatorBuilder == null),

lib/src/types/page_introduction.dart

@@ -102,7 +102,7 @@ class _MultiPageIntroductionScreenState
             mainAxisAlignment: MainAxisAlignment.spaceBetween,
             children: [
               if (widget.options.controlMode ==
-                  IntroductionControlMode.twoButton) ...[
+                  IntroductionControlMode.previousNextButton) ...[
                 Padding(
                   padding: const EdgeInsets.only(right: 16.0),
                   child: SizedBox(
@@ -149,7 +149,7 @@ class _MultiPageIntroductionScreenState
                         animation: _controller,
                         builder: (context, _) {
                           if (widget.options.controlMode ==
-                              IntroductionControlMode.oneButton) {
+                              IntroductionControlMode.singleButton) {
                             return IntroductionOneButton(
                               controller: _controller,
                               next: _isNext(pages),