Refactoring, housekeeping, documentation

Add a class diagram. Still needs some details.
Refactor to better respect SOLID principles.
Housekeeping, move and rename classes/files.

app/include/ConfigManager.h

@@ -0,0 +1,28 @@
+#ifndef CONFIGMANAGER_H_
+#define CONFIGMANAGER_H_
+
+#include <memory>
+#include <vector>
+
+#include <nlohmann/json.hpp>
+
+#include <fan/Fan.h>
+
+#define CONFIG_FILE "/etc/fantasize/config.json"
+
+using json = nlohmann::json;
+
+class ConfigManager {
+public:
+  ConfigManager();
+  ~ConfigManager();
+
+  void WriteConfig();
+
+  void SaveFans(std::vector<std::shared_ptr<Fan>> fans);
+
+private:
+  json mConfig;
+};
+
+#endif // CONFIGMANAGER_H_