docs(lf): added logos of lf2302 and lf2303

Author: Lemon73-Computing

content/ja/events/lf.md

@@ -78,10 +78,14 @@ LF は別名 Lemonade Flash や、Lemon's Flower day などの異名もありま
 
 <https://youtu.be/1bH-2bTC8WA>
 
+![lf2302](/images/lemon-festival/lf2302.png)
+
 #### LF2303 - 夏 - 
 
 <https://youtu.be/7PAvvLX0DUE>
 
+![lf2303](/images/lemon-festival/lf2303.png)
+
 #### LF2304 mini
 
 <https://youtu.be/JXrlsXaj2Aw>