Update and rename renovate.json to .github/renovate.json

.github/renovate.json

@@ -0,0 +1,6 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "extends": [
+    "github>jellyfin/.github//renovate-presets/dotnet"
+  ]
+}

renovate.json

@@ -1,6 +0,0 @@
-{
-    "$schema": "https://docs.renovatebot.com/renovate-schema.json",
-    "extends": [
-        "config:base"
-    ]
-}