📝 Added jsdoc comments to DataService.

Trying my best to keep this up.

src/app/services/data.service.ts

@@ -2,6 +2,12 @@ import { Injectable } from '@angular/core';
 import { HttpClient } from '@angular/common/http';
 import { Observable } from 'rxjs';
 
+/**
+ * The DataService handles all data traffic to and from the API.
+ * @example Get a song by id.
+ * // returns something like {result: {id: 0, name: "Thunderstruck", artist: "AC/DC"}}
+ * DataService.getSong(0);
+ */
 @Injectable({
   providedIn: 'root'
 })
@@ -10,27 +16,52 @@ export class DataService {
   private apiUrl = 'http://localhost:673';
 
   constructor(private http: HttpClient) { }
-
+  /**
+   * @param type The type of the thing you want to get. The type is a string containing either 'artist', 'album' or 'song'.
+   * @param id The id of the artist. It can be a number representing the id, multiple numbers seperated by commas or the string 'all'.
+   * @returns An Observable<object> containing the returned data from the API.
+   */
   get(type: string, id: string | number): Observable<object> {
     return this.http.get(`${this.apiUrl}/get/${type}/${id}`);
   }
 
+  /**
+   * @param id The id of the artist. It can be a number representing the id, multiple numbers seperated by commas or the string 'all'.
+   * @returns An Observable<object> containing the returned data from the API.
+   */
   getSong(id: number | string): Observable<object> {
     return this.get('song', id);
   }
 
+  /**
+   * @param id The id of the artist. It can be a number representing the id, multiple numbers seperated by commas or the string 'all'.
+   * @returns An Observable<object> containing the returned data from the API.
+   */
   getAlbum(id: number | string): Observable<object> {
     return this.get('album', id);
   }
 
+  /**
+   * A function to get one, multiple or all artists.
+   * @param id The id of the artist. It can be a number representing the id, multiple numbers seperated by commas or the string 'all'.
+   * @returns An Observable<object> containing the returned data from the API.
+   */
   getArtist(id: number | string): Observable<object> {
   return this.get('artist', id);
   }
 
+  /**
+   * A function to get all albums from the API.
+   * @returns An Observable<object> containing the returned data from the API.
+   */
   getAllAlbums(): Observable<object> {
     return this.get('album', 'all');
   }
 
+  /**
+   * A function to get all artists from the API.
+   * @returns An Observable<object> containing the returned data from the API.
+   */
   getAllArtists(): Observable<object> {
     return this.get('artist', 'all');
   }