Help: Move-capture help page path

Previously it was reference-captured, causing crash because of stack
use after return.

Userland/Applications/Help/MainWidget.cpp

@@ -234,9 +234,9 @@ ErrorOr<void> MainWidget::initialize_fallibles(GUI::Window& window)
     TRY(go_menu->try_add_action(*m_go_home_action));
 
     auto help_menu = TRY(window.try_add_menu("&Help"));
-    String const help_page_path = TRY(TRY(try_make_ref_counted<Manual::PageNode>(Manual::sections[1 - 1], TRY(String::from_utf8("Help"sv))))->path());
+    String help_page_path = TRY(TRY(try_make_ref_counted<Manual::PageNode>(Manual::sections[1 - 1], TRY(String::from_utf8("Help"sv))))->path());
     TRY(help_menu->try_add_action(GUI::CommonActions::make_command_palette_action(&window)));
-    TRY(help_menu->try_add_action(GUI::Action::create("&Contents", { Key_F1 }, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/filetype-unknown.png"sv)), [&](auto&) {
+    TRY(help_menu->try_add_action(GUI::Action::create("&Contents", { Key_F1 }, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/filetype-unknown.png"sv)), [this, help_page_path = move(help_page_path)](auto&) {
         open_page(help_page_path);
     })));
     TRY(help_menu->try_add_action(GUI::CommonActions::make_about_action("Help", TRY(GUI::Icon::try_create_default_icon("app-help"sv)), &window)));