Code + comment cleanup for the entities

ref #39

src/models/entities/Runner.ts

@@ -7,44 +7,52 @@ import { RunnerGroup } from "./RunnerGroup";
 import { Scan } from "./Scan";
 
 /**
- * Defines a runner.
+ * Defines the runner entity.
+ * Runners differ from participants in being able to actually accumulate a ran distance through scans.
+ * Runner's get organized in groups.
 */
 @ChildEntity()
 export class Runner extends Participant {
   /**
    * The runner's associated group.
+   * Can be a runner team or organisation.
    */
   @IsNotEmpty()
   @ManyToOne(() => RunnerGroup, group => group.runners, { nullable: false })
   group: RunnerGroup;
 
   /**
-   * Used to link runners to donations.
+   * The runner's associated distanceDonations.
+   * Used to link runners to distanceDonations in order to calculate the donation's amount based on the distance the runner ran.
    */
   @OneToMany(() => DistanceDonation, distanceDonation => distanceDonation.runner, { nullable: true })
   distanceDonations: DistanceDonation[];
 
   /**
-   * Used to link runners to cards.
+   * The runner's associated cards.
+   * Used to link runners to cards - yes a runner be associated with multiple cards this came in handy in the past.
    */
   @OneToMany(() => RunnerCard, card => card.runner, { nullable: true })
   cards: RunnerCard[];
 
   /**
-   * Used to link runners to a scans
+   * The runner's associated scans.
+   * Used to link runners to scans (valid and fraudulant).
    */
   @OneToMany(() => Scan, scan => scan.runner, { nullable: true })
   scans: Scan[];
 
   /**
    * Returns all valid scans associated with this runner.
+   * This is implemented here to avoid duplicate code in other files.
    */
   public get validScans(): Scan[] {
     return this.scans.filter(scan => { scan.valid === true });
   }
 
   /**
-   * Returns the total distance ran by this runner.
+   * Returns the total distance ran by this runner based on all his valid scans.
+   * This is implemented here to avoid duplicate code in other files.
   */
   @IsInt()
   public get distance(): number {