Adicionado alerta de desafios indisponíveis

Author: Lorenalgm

frontend/src/pages/Challenges/index.js

@@ -94,7 +94,7 @@ export default function Challenges({ location }) {
                 </S.Filters>
             </S.Head>
 
-            {loading && <ChallengesSkeleton cards={6} />}
+            {loading && <S.Alert>Em manutenção! Os desafios estarão disponíveis novamente em breve :)</S.Alert>}
             {!loading && (
                 <S.Section>
                     {challenges.map((challenge) => {

frontend/src/pages/Challenges/styled.js

@@ -2,6 +2,12 @@ import styled from 'styled-components';
 import media from 'styled-media-query';
 import chevronDown from '../../assets/chevron-down.svg';
 
+export const Alert = styled.form`
+    color: white;
+    text-align: center;
+    margin-top: 3em;
+`;
+
 export const Section = styled.section`
     margin-top: 3%;
     display: flex;