OTA updates (#96)

## Summary

* Adds support for OTA
  * Gets latest firmware bin from latest GitHub release
* I have noticed it be a little flaky unpacking the JSON and
occasionally failing to start

src/activities/settings/SettingsActivity.h

@@ -3,16 +3,15 @@
 #include <freertos/semphr.h>
 #include <freertos/task.h>
 
-#include <cstdint>
 #include <functional>
 #include <string>
 #include <vector>
 
-#include "../Activity.h"
+#include "activities/ActivityWithSubactivity.h"
 
 class CrossPointSettings;
 
-enum class SettingType { TOGGLE, ENUM };
+enum class SettingType { TOGGLE, ENUM, ACTION };
 
 // Structure to hold setting information
 struct SettingInfo {
@@ -22,7 +21,7 @@ struct SettingInfo {
   std::vector<std::string> enumValues;
 };
 
-class SettingsActivity final : public Activity {
+class SettingsActivity final : public ActivityWithSubactivity {
   TaskHandle_t displayTaskHandle = nullptr;
   SemaphoreHandle_t renderingMutex = nullptr;
   bool updateRequired = false;
@@ -32,11 +31,11 @@ class SettingsActivity final : public Activity {
   static void taskTrampoline(void* param);
   [[noreturn]] void displayTaskLoop();
   void render() const;
-  void toggleCurrentSetting() const;
+  void toggleCurrentSetting();
 
  public:
   explicit SettingsActivity(GfxRenderer& renderer, InputManager& inputManager, const std::function<void()>& onGoHome)
-      : Activity("Settings", renderer, inputManager), onGoHome(onGoHome) {}
+      : ActivityWithSubactivity("Settings", renderer, inputManager), onGoHome(onGoHome) {}
   void onEnter() override;
   void onExit() override;
   void loop() override;