Fix a few typos

As part of packaging Prism Launcher for Debian, I have run a package linter
called lintian which found a few spelling errors throughout the source.

I am not a fan of contributions that only fix cosmetics like spelling errors,
but Debian encourages forwarding this stuff upstream instead of letting it get
fixed naturally over time.

Signed-off-by: Ben Westover <me@benthetechguy.net>

launcher/Application.cpp

@@ -817,7 +817,7 @@ Application::Application(int& argc, char** argv) : QApplication(argc, argv)
         m_icons.reset(new IconList(instFolders, setting->get().toString()));
         connect(setting.get(), &Setting::SettingChanged,
                 [&](const Setting&, QVariant value) { m_icons->directoryChanged(value.toString()); });
-        qDebug() << "<> Instance icons intialized.";
+        qDebug() << "<> Instance icons initialized.";
     }
 
     // Themes