Add Steam+DpadUP binding (#8)

* Add Steam+DpadUP binding [ci skip]

Windows on SteamDeck generally needs a hotkey available to use with upscaling applications as many games crash when attempting to render exclusive fullscreen.

Added the following binding:
- Steam + DPadUP = Ctrl+Alt+U

* Include new Steam+DPadUP binding in readme

Added keybind to table list. Included instructions on how the binding can be used to set up a full screen scaling toggle.

README.md

@@ -217,6 +217,7 @@ Of course you will have access to all described shortcuts.
 | STEAM + R2                 | Mouse Left Click       | Mouse Left Click       |                        | Mouse Left Click       |
 | STEAM + Left Pad Press     | Mouse Right Click      | Mouse Right Click      |                        | Mouse Right Click      |
 | STEAM + Right Pad Press    | Mouse Left Click       | Mouse Left Click       |                        | Mouse Left Click       |
+| Steam + Up Pad Press       | Ctrl + Alt + U         | Ctrl + Alt + U         |                        |                        |
 | Left Pad                   | Mouse Scroll           |                        |                        |                        |
 | Left Joystick              | Mouse Scroll           |                        |                        |                        |
 | Right Joystick             | Mouse Trackpad         |                        |                        |                        |
@@ -252,6 +253,20 @@ to make `SteamController.exe` the one mapping those.
 1. In a new window click `DELETE`.
 1. Now click `B` or `DONE`.
 
+### 4.4. Fullscreen Scaling Hotkey (Steam + Up Pad Press)
+
+Many games in Windows will crash when attempting to start in fullscreen.  To have a fullscreen experience on the Steam Deck, you can use this keybind in any fullscreen scaling application to provide a shortcut capable of toggling the scaling.
+
+Example of Scaling software: https://store.steampowered.com/app/993090/Lossless_Scaling/
+
+To configure the hotkey in Lossless Scaling:
+1. Launch Lossless Scaling
+1. Open "Settings"
+1. Select the "Scale hotkey"
+1. Press "Steam+DPad Up"
+1. Verify that the hotkey was set to "Ctrl + Alt + U"
+1. Close the settings dialog
+
 ## 5. Risks
 
 **This software is provided on best-effort basis and can break your SteamDeck.** It does a direct manipulation

SteamController/Profiles/DefaultGuideShortcutsProfile.cs

@@ -103,6 +103,11 @@ namespace SteamController.Profiles
             {
                 c.Keyboard.KeyPress(VirtualKeyCode.ESCAPE);
             }
+            
+            // Additional binding for tool hotkeys (Lossless Fullscreen is nice)
+            if (c.Steam.BtnDpadUp.HoldOnce(ShortcutConsumed)) {
+                c.Keyboard.KeyPress(new List<VirtualKeyCode> { VirtualKeyCode.LCONTROL, VirtualKeyCode.LMENU }, VirtualKeyCode.VK_U);
+            }
         }
 
         protected void EmulateScrollOnLPad(Context c)