apply styles to SystemVersion

packages/app/src/components/SystemVersion.scss

@@ -0,0 +1,6 @@
+.system-version {
+  position: fixed;
+  right: 0.5em;
+  bottom: 0;
+  opacity: 0.6;
+}

packages/app/src/components/SystemVersion.tsx

@@ -3,6 +3,8 @@ import React from 'react';
 import { useGrowiVersion } from '~/stores/context';
 import { useShortcutsModal } from '~/stores/modal';
 
+import './SystemVersion.scss';
+
 const SystemVersion = (): JSX.Element => {
 
   const { open: openShortcutsModal } = useShortcutsModal();

packages/app/src/styles/_layout.scss

@@ -131,10 +131,3 @@ body.growi-layout-fluid .grw-container-convertible {
     }
   }
 }
-
-.system-version {
-  position: fixed;
-  right: 0.5em;
-  bottom: 0;
-  opacity: 0.6;
-}