[Glitch] Don't reset scroll when using hotkeys to focus columns, add hotkey 0 to scroll to top

Port 9334bd9ede to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/components/hotkeys/index.tsx

@@ -112,6 +112,7 @@ const hotkeyMatcherMap = {
   openProfile: just('p'),
   moveDown: just('j'),
   moveUp: just('k'),
+  moveToTop: just('0'),
   toggleHidden: just('x'),
   toggleSensitive: just('h'),
   toggleComposeSpoilers: optionPlus('x'),