rename header files from *.h to *.hpp

src/windowmanager.hpp

@@ -0,0 +1,36 @@
+#pragma once
+
+#include "widgets/mainwindow.hpp"
+
+#include <mutex>
+
+namespace chatterino {
+
+class WindowManager
+{
+public:
+    static WindowManager &getInstance()
+    {
+        return instance;
+    }
+
+    void layoutVisibleChatWidgets(Channel *channel = nullptr);
+    void repaintVisibleChatWidgets(Channel *channel = nullptr);
+    void repaintGifEmotes();
+    void updateAll();
+
+    widgets::MainWindow &getMainWindow();
+
+    void load();
+    void save();
+
+private:
+    static WindowManager instance;
+
+    WindowManager();
+
+    std::mutex _windowMutex;
+    widgets::MainWindow *_mainWindow;
+};
+
+}  // namespace chatterino