UI: Add Help menu action to show What's New dialog

UI/data/locale/en-US.ini

@@ -819,6 +819,7 @@ Basic.MainMenu.Help="&Help"
 Basic.MainMenu.Help.HelpPortal="Help &Portal"
 Basic.MainMenu.Help.Website="Visit &Website"
 Basic.MainMenu.Help.Discord="Join &Discord Server"
+Basic.MainMenu.Help.WhatsNew="What's New"
 Basic.MainMenu.Help.Logs="&Log Files"
 Basic.MainMenu.Help.Logs.ShowLogs="&Show Log Files"
 Basic.MainMenu.Help.Logs.UploadCurrentLog="Upload &Current Log File"

UI/forms/OBSBasic.ui

@@ -532,6 +532,7 @@
     <addaction name="separator"/>
     <addaction name="actionRepair"/>
     <addaction name="actionCheckForUpdates"/>
+    <addaction name="actionShowWhatsNew"/>
     <addaction name="actionShowAbout"/>
     <addaction name="actionShowMacPermissions"/>
     <addaction name="separator"/>
@@ -2201,6 +2202,11 @@
     <string>Basic.MainMenu.Help.Discord</string>
    </property>
   </action>
+  <action name="actionShowWhatsNew">
+   <property name="text">
+    <string>Basic.MainMenu.Help.WhatsNew</string>
+   </property>
+  </action>
   <action name="actionShowAbout">
    <property name="text">
     <string>Basic.MainMenu.Help.About</string>

UI/window-basic-main.cpp

@@ -2176,6 +2176,11 @@ void OBSBasic::OBSInit()
 	}
 #endif
 
+#ifndef WHATSNEW_ENABLED
+	delete ui->actionShowWhatsNew;
+	ui->actionShowWhatsNew = nullptr;
+#endif
+
 	UpdatePreviewProgramIndicators();
 	OnFirstLoad();
 
@@ -7964,6 +7969,25 @@ void OBSBasic::on_actionDiscord_triggered()
 	QDesktopServices::openUrl(url);
 }
 
+void OBSBasic::on_actionShowWhatsNew_triggered()
+{
+#ifdef WHATSNEW_ENABLED
+	if (introCheckThread && introCheckThread->isRunning())
+		return;
+	if (!cef)
+		return;
+
+	config_set_int(App()->GlobalConfig(), "General", "InfoIncrement", -1);
+
+	WhatsNewInfoThread *wnit = new WhatsNewInfoThread();
+	connect(wnit, &WhatsNewInfoThread::Result, this,
+		&OBSBasic::ReceivedIntroJson, Qt::QueuedConnection);
+
+	introCheckThread.reset(wnit);
+	introCheckThread->start();
+#endif
+}
+
 void OBSBasic::on_actionShowSettingsFolder_triggered()
 {
 	char path[512];

UI/window-basic-main.hpp

@@ -1034,6 +1034,7 @@ private slots:
 	void on_actionViewCurrentLog_triggered();
 	void on_actionCheckForUpdates_triggered();
 	void on_actionRepair_triggered();
+	void on_actionShowWhatsNew_triggered();
 
 	void on_actionShowCrashLogs_triggered();
 	void on_actionUploadLastCrashLog_triggered();