Add Nextra Detection

src/technologies/n.json

@@ -658,6 +658,19 @@
     "scriptSrc": "(?:api|sdk)\\.nextsale\\.io/",
     "website": "https://nextsale.io"
   },
+  "Nextra": {
+    "cats": [
+      57
+    ],
+    "description": "Nextra is Next.js based static site generator.",
+    "dom": "[class*='.nextra-container']",
+    "icon": "Next.js.svg",
+    "implies": [
+      "Next.js"
+    ],
+    "oss": true,
+    "website": "https://nextra.vercel.app/"
+  },
   "NexusPIPE": {
     "cats": [
       16