make virtual scrolling optional in case people want to be able to ctrl-f all page

src/i18n/en.json

@@ -375,6 +375,7 @@
       "false": "no",
       "true": "yes"
     },
+    "virtual_scrolling": "Optimize timeline rendering",
     "fun": "Fun",
     "greentext": "Meme arrows",
     "notifications": "Notifications",

src/i18n/fi.json

@@ -228,7 +228,8 @@
     "values": {
       "false": "pois päältä",
       "true": "päällä"
-    }
+    },
+    "virtual_scrolling": "Optimoi aikajanan suorituskykyä"
   },
   "time": {
     "day": "{0} päivä",