centralise niri-noctalia calculator config

dotfiles/shared/niri-shared.kdl

@@ -33,6 +33,7 @@ layout {
 }
 binds {
     Mod+D hotkey-overlay-title="Application launcher" { spawn "noctalia" "msg" "panel-toggle" "launcher"; }
+    Mod+C hotkey-overlay-title="Open calculator" { spawn "noctalia" "msg" "panel-toggle" "yuuto/calculator:panel"; }
     Mod+Return hotkey-overlay-title="Open terminal (Kitty)" { spawn "kitty"; }
     Mod+O hotkey-overlay-title="Open Obsidian" { spawn "obsidian"; }
     Mod+G hotkey-overlay-title="Open GitHub Desktop" { spawn "github-desktop"; }
@@ -83,6 +84,7 @@ binds {
 
     Print { screenshot; }
     Shift+Print { screenshot-window; }
+    Mod+Print { screenshot-screen; }
 
     Mod+Slash { spawn "niri-scratch-workspace-toggle"; }
     Mod+Shift+Slash { move-window-to-workspace "x" focus=false; }