Add XenForo addon.json schema (#5499)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 3 people

src/api/json/catalog.json

@@ -7106,6 +7106,12 @@
       "fileMatch": ["wrangler.json", "wrangler.jsonc", "wrangler.toml"],
       "url": "https://www.unpkg.com/wrangler/config-schema.json"
     },
+    {
+      "name": "XenForo add-on manifest",
+      "description": "A manifest describing a XenForo add-on",
+      "fileMatch": [],
+      "url": "https://docs.xenforo.com/schema/addon.schema.json"
+    },
     {
       "name": "JSON-stat 2.0",
       "description": "JSON-stat 2.0",