Add basic lua scripting capabilities (#4341)

The scripting capabilities is locked behind a cmake flag, and is not enabled by default.

Co-authored-by: nerix <nerixdev@outlook.de>
Co-authored-by: pajlada <rasmus.karlsson@pajlada.com>

src/widgets/dialogs/SettingsDialog.cpp

@@ -20,6 +20,7 @@
 #include "widgets/settingspages/ModerationPage.hpp"
 #include "widgets/settingspages/NicknamesPage.hpp"
 #include "widgets/settingspages/NotificationPage.hpp"
+#include "widgets/settingspages/PluginsPage.hpp"
 
 #include <QDialogButtonBox>
 #include <QFile>
@@ -216,6 +217,9 @@ void SettingsDialog::addTabs()
     this->addTab([]{return new ModerationPage;},       "Moderation",     ":/settings/moderation.svg", SettingsTabId::Moderation);
     this->addTab([]{return new NotificationPage;},     "Live Notifications",  ":/settings/notification2.svg");
     this->addTab([]{return new ExternalToolsPage;},    "External tools", ":/settings/externaltools.svg");
+#ifdef CHATTERINO_HAVE_PLUGINS
+    this->addTab([]{return new PluginsPage;},          "Plugins",        ":/settings/plugins.svg");
+#endif
     this->ui_.tabContainer->addStretch(1);
     this->addTab([]{return new AboutPage;},            "About",          ":/settings/about.svg", SettingsTabId(), Qt::AlignBottom);
     // clang-format on