Update plugin index

Author: github-actions[bot]

plugins/index.json

@@ -94,6 +94,11 @@
     "desc": "Kotlin plugin",
     "homepage": "https://github.com/version-fox/vfox-kotlin"
   },
+  {
+    "name": "kubectl",
+    "desc": "Kubectl plugin",
+    "homepage": "https://github.com/ahai-code/vfox-kubectl"
+  },
   {
     "name": "lua",
     "desc": "lua vfox plugin. Use the vfox to manage multiple lua versions on Linux /Darwin MacOS / Windows.",