Localize the Shortcut guide PowerToy (#199) (#1126)

* Localized shortcut_guide.cpp

* localized overlay_window.cpp

* formatting changes

* Localize overlay window

* removed the README link from the set of localized resources

* Typo: changed upper to lower

src/modules/shortcut_guide/shortcut_guide.h

@@ -35,6 +35,7 @@ public:
     virtual void destroy() override;
 
 private:
+    std::wstring app_name;
     std::unique_ptr<TargetState> target_state;
     std::unique_ptr<D2DOverlayWindow> winkey_popup;
     bool _enabled = false;