yh4f adding sidebar, registration and mastodon (#4673)

The sidebar, registration link and Mastodon link is add.
All text changes are agreed with @anaghz

Reviewed-on: #4673
Co-authored-by: Bonnie Mehring <bonnie@fsfe.org>
Co-committed-by: Bonnie Mehring <bonnie@fsfe.org>

fsfe.org/news/2024/news-20241211-01.en.xhtml

@@ -395,8 +395,23 @@ best of luck with your future plans and a lot of success with your
 projects!
 </p>
 </div>
+	
+<hr />
 
+<p>The 2025 edition of Youth Hacking 4 Freedom will starton 01.01.2025. You can already 
+	register <a href="yh4f.org/register">now</a>. Check out the <a 
+	href="https://yh4f.org">YH4F website</a> to find out all the details of 
+	this competition or feel free to reach out to the organisers via <a 
+	href="mailto:yh4f@fsfe.org">mail</a>!
+	</p>
+	
+	
 </body>
+	
+	<sidebar promo="our-work">
+	<cite><a href="https://yh4f.org/register"><strong>Registration</strong></a></cite> is open for the next edition, YH4F 2025, that will start on 1 January 2025. This competition is running thanks to our donors and sponsors. Please consider supporting our work. 
+	</sidebar>
+	
 
 <tags>
 <tag key="front-page"/>
@@ -406,7 +421,8 @@ projects!
 <tag key="yh4f-project">Youth Hacking 4 Freedom - Project</tag>
 </tags>
 		
-<discussion href=""/>  
+<discussion href="https://mastodon.social/deck/@fsfe/113634952636401283"/>  
+
 <image url="https://pics.fsfe.org/uploads/original/6e/c2/9ced0e9d41702570bf6e0ce0399d.jpg"
  alt="picture with different pieces to build a led sign with the logo of Youth Hacking for Freedom, among them two plastic boards with the logo, a led string, a usb type c cable and stickers"/>