Moved to a "cleaner" directory structure

ref #11

src/models/entities/FixedDonation.ts

@@ -0,0 +1,18 @@
+import { Entity, Column, ChildEntity } from "typeorm";
+import { IsInt, IsPositive, } from "class-validator";
+import { Donation } from "./Donation";
+
+/**
+ * Defines a fixed donation.
+*/
+@ChildEntity()
+export class FixedDonation extends Donation {
+
+  /**
+   * The donation's amount in cents (or whatever your currency's smallest unit is.).
+   */
+  @Column()
+  @IsInt()
+  @IsPositive()
+  amount: number;
+}