Frontend updates and changes

- Remove items/runes separate pages, put everything into a "build" page.
- Show summoner spells.
- Add a build variant selector, that for now only selects runes

frontend/eslint.config.mjs

@@ -30,7 +30,10 @@ export default withNuxt([
         ChampionsResponse: 'readonly',
         ChampionResponse: 'readonly',
         ItemResponse: 'readonly',
-        MatchupData: 'readonly'
+        MatchupData: 'readonly',
+        Item: 'readonly',
+        SummonerSpell: 'readonly',
+        Perk: 'readonly'
       }
     },
     rules: {