Add ShopType enum

src/main/java/com/alttd/playershops/shop/ShopType.java

@@ -0,0 +1,23 @@
+package com.alttd.playershops.shop;
+
+import com.alttd.playershops.config.ShopMessageConfig;
+
+public enum ShopType {
+
+    SELL,
+    BUY,
+    GAMBLE,
+    BARTER;
+
+    private final ShopMessageConfig shopMessageConfig;
+
+    ShopType() {
+        this.shopMessageConfig = new ShopMessageConfig(toString());
+    }
+
+    @Override
+    public String toString() {
+        return name().toLowerCase();
+    }
+
+}