poll are optional + fix typo

Detailed description.

src/components/Editing/CustomLink.tsx

@@ -22,7 +22,7 @@ const CustomLink: React.FC<EcolyoLinkProps> = ({
       link: 'consumption',
     },
     {
-      displayTitle: 'Ecogestes',
+      displayTitle: 'Écogestes',
       link: 'ecogestures',
     },
     {

src/components/Poll/Poll.tsx

@@ -31,7 +31,7 @@ const Poll: React.FC<PollProps> = ({
 
   return (
     <div className="poll">
-      <h2>Ajouter un sondage</h2>
+      <h2>Ajouter un sondage (Optionnel)</h2>
       <p className="title">Lien</p>
       <input
         type="text"