Refactor radar chart and improve UI elements

- Updated radar chart to use abbreviated category labels for better readability.
- Enhanced chart visibility with improved grid and axis styling.
- Added a gradient background to the radar area for a more polished look.
- Simplified links in JSON files for backend, cloud, and devops skills.
- Adjusted HomePage text for clarity and consistency.

app/page.tsx

@@ -124,7 +124,7 @@ export default function HomePage() {
                 Vue d'ensemble de vos compétences
               </h3>
               <p className="text-slate-400 text-sm">
-                Graphique radar représentant votre niveau moyen par catégorie
+                Radar chart représentant votre niveau par catégorie
               </p>
             </div>
             <div className="h-80">
@@ -155,8 +155,8 @@ export default function HomePage() {
                 const currentSkillCategory = skillCategories.find(
                   (sc) => sc.category === category.category
                 );
-                const CategoryIcon = currentSkillCategory 
-                  ? getCategoryIcon(currentSkillCategory.icon) 
+                const CategoryIcon = currentSkillCategory
+                  ? getCategoryIcon(currentSkillCategory.icon)
                   : null;
 
                 return (