Add link to source code

public/index.html

@@ -21,7 +21,7 @@
 			<textarea id="text-output" class="form-control flex-fill" readonly></textarea>
 		</div>
 	</div>
-	<footer style="text-align: center"><a href="https://legal.cccv.de">Impressum/Privacy Policy</a></footer>
+	<footer style="text-align: center"><a href="https://legal.cccv.de">Impressum/Privacy Policy</a> - <a href="https://git.cccv.de/infra/static-pages/convert.md.cccv.de">Source Code</a></footer>
 </div>
 
 <script>