Added jsdoc style class documentation

ref #3

src/models/Track.ts

@@ -7,6 +7,12 @@ import {
   IsString,
 } from "class-validator";
 
+/**
+ * @classdesc Defines a track of given length.
+ * @property {number} id - Autogenerated unique id
+ * @property {string} name - The track's name
+ * @property {number} lenth - The track's length in meters
+*/
 @Entity()
 export class Track {
   @PrimaryGeneratedColumn()