Add keybind for purchase dialog ALL button

Settings.cs

@@ -68,6 +68,7 @@ namespace UIFixes
         public static ConfigEntry<bool> ShowRequiredQuest { get; set; }
         public static ConfigEntry<bool> AutoExpandCategories { get; set; }
         public static ConfigEntry<bool> KeepAddOfferOpen { get; set; }
+        public static ConfigEntry<KeyboardShortcut> PurchaseAllKeybind { get; set; }
         public static ConfigEntry<bool> KeepAddOfferOpenIgnoreMaxOffers { get; set; } // Advanced
         public static ConfigEntry<bool> RememberAutoselectSimilar { get; set; } // Advanced
 
@@ -333,6 +334,15 @@ namespace UIFixes
                     null,
                     new ConfigurationManagerAttributes { })));
 
+            configEntries.Add(PurchaseAllKeybind = config.Bind(
+                InspectSection,
+                "Purchase Dialog ALL Shortcut",
+                new KeyboardShortcut(KeyCode.A),
+                new ConfigDescription(
+                    "Keybind to set the quantity to all in the item purchase dialog. Equivalent to clicking the ALL button.",
+                    null,
+                    new ConfigurationManagerAttributes { })));
+
             configEntries.Add(KeepAddOfferOpenIgnoreMaxOffers = config.Bind(
                 FleaMarketSection,
                 "Keep Add Offer Window Open: Ignore Max Offers",