add screenshots url

Author: alainm23

data/tomato.metainfo.xml.in

@@ -15,15 +15,15 @@
   <screenshots>
     <screenshot type="default">
       <caption>Pomodoro time</caption>
-      <image>https://raw.githubusercontent.com/ellie-commons/tomato/master/data/screenshots/pomodoro.png</image>
+      <image>https://github.com/ellie-commons/tomato/blob/main/data/screenshots/pomodoro.png?raw=true</image>
     </screenshot>
     <screenshot>
       <caption>Start page</caption>
-      <image>https://raw.githubusercontent.com/ellie-commons/tomato/master/data/screenshots/start.png</image>
+      <image>https://github.com/ellie-commons/tomato/blob/main/data/screenshots/start.png?raw=true</image>
     </screenshot>
     <screenshot>
       <caption>Short break time</caption>
-      <image>https://raw.githubusercontent.com/ellie-commons/tomato/master/data/screenshots/break.png</image>
+      <image>https://github.com/ellie-commons/tomato/blob/main/data/screenshots/break.png?raw=true</image>
     </screenshot>
   </screenshots>