Refactoring, housekeeping, documentation

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

app/src/pwm/PWMControlFacade.cxx

@@ -0,0 +1,37 @@
+#include <filesystem>
+#include <iostream>
+#include <regex>
+
+#include <pwm/PWMControlFacade.h>
+
+using namespace std;
+namespace fs = std::filesystem;
+
+vector<shared_ptr<PWMControl>> PWMControlFacade::PWMControls() {
+  vector<shared_ptr<PWMControl>> controls;
+
+  const regex re_ctrl_enable("pwm[0-9]_enable");
+  const regex re_ctrl_mode("pwm[0-9]_mode");
+  const regex re_ctrl("pwm[0-9]");
+
+  if (!fs::exists(HWMON_BASE_PATH)) {
+    cout << HWMON_BASE_PATH << " doesn't exist" << endl;
+  } else {
+    for (const fs::directory_entry &hwmon_device :
+         fs::directory_iterator{HWMON_BASE_PATH}) {
+
+      for (const fs::directory_entry &control :
+           fs::directory_iterator{hwmon_device}) {
+        auto filename = control.path().filename().string();
+
+        if (regex_match(filename, re_ctrl)) {
+          auto controlPath = control.path().string();
+
+          controls.push_back(make_shared<PWMControl>(controlPath));
+        }
+      }
+    }
+  }
+
+  return controls;
+}