finish up base recruitment system

src/classes/guildUpgrades/RecruitmentCapacityUpgrade.ts

@@ -0,0 +1,36 @@
+import {GuildUpgrade} from "@/classes/GuildUpgrade";
+import type MaxLevellable from "@/classes/MaxLevellable";
+
+export default class AdventurerCapacityUpgrade extends GuildUpgrade implements MaxLevellable {
+
+    maxLevel: number;
+
+    constructor(level: number = 1) {
+        super();
+        this.level = level;
+        this.nextLevelCost = this.getCostForLevel(this.level);
+        this.guildLevelRequirement = 3;
+        this.maxLevel = 3;
+    }
+
+    upgrade(): void {
+        this.level += 1;
+        this.nextLevelCost = this.getCostForLevel(this.level);
+    }
+
+    getCostForLevel(level: number): number {
+        if (level === 1) return 1500;
+        return Math.floor(1500 * (level * 4));
+    }
+
+    /**
+     * Returns the number of adventurers the guild can have
+     */
+    getRecruitmentCapacity(): number {
+        return this.level ;
+    }
+
+    isMaxLevel(): boolean {
+        return this.level >= this.maxLevel;
+    }
+}