updated readme to include preview of megumin theme

README.md

@@ -8,4 +8,6 @@ two alternatives when it comes to background. one has tenshi eating a corndog on
 ## lain-darkgray
 ![screenshot of lain-darkgray](https://git.lain.church/vala/pleroma-lain-themes/raw/branch/master/lain_darkgray.png)
 ## lain-pinktransparent
-![screenshot of lain-pinktransparent](https://git.lain.church/vala/pleroma-lain-themes/raw/branch/master/lain_pinktransparent.png)
+![screenshot of lain-pinktransparent](https://git.lain.church/vala/pleroma-lain-themes/raw/branch/master/lain_pinktransparent.png)
+## megumin
+![screenshot of megumin](https://git.lain.church/vala/pleroma-lain-themes/raw/branch/master/megumin.jpg)