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.

data/skills/cloud.json

@@ -6,10 +6,7 @@
       "id": "aws",
       "name": "Amazon Web Services",
       "description": "Plateforme de services cloud d'Amazon",
-      "links": [
-        "https://aws.amazon.com/",
-        "https://docs.aws.amazon.com/"
-      ]
+      "links": ["https://aws.amazon.com/", "https://docs.aws.amazon.com/"]
     },
     {
       "id": "azure",
@@ -24,10 +21,7 @@
       "id": "gcp",
       "name": "Google Cloud Platform",
       "description": "Services cloud de Google",
-      "links": [
-        "https://cloud.google.com/",
-        "https://cloud.google.com/docs"
-      ]
+      "links": ["https://cloud.google.com/", "https://cloud.google.com/docs"]
     },
     {
       "id": "terraform",
@@ -69,10 +63,7 @@
       "id": "s3",
       "name": "Amazon S3",
       "description": "Service de stockage d'objets d'AWS",
-      "links": [
-        "https://aws.amazon.com/s3/",
-        "https://docs.aws.amazon.com/s3/"
-      ]
+      "links": ["https://aws.amazon.com/s3/", "https://docs.aws.amazon.com/s3/"]
     },
     {
       "id": "ec2",