Added deepL translation api and made little improvements

src/app/service/deepL.service.ts

@@ -0,0 +1,25 @@
+import { Injectable } from '@angular/core';
+import { HttpClient, HttpParams } from '@angular/common/http';
+import { Observable } from 'rxjs';
+import { environment } from '../../environments/environment';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class DeepLService {
+
+  private apiUrl = 'https://api-free.deepl.com/v2/translate';
+  private apiKey = environment.deepLApiKey;
+
+  constructor(private http: HttpClient) { }
+
+  translate(text: string, targetLang: string): Observable<any> {
+    const params = new HttpParams()
+      .set('auth_key', this.apiKey)
+      .set('text', text)
+      .set('target_lang', targetLang);
+
+    return this.http.post(this.apiUrl, params);
+  }
+
+}