Add support for Codex

Documentation: https://developers.openai.com/codex/plugins/build

.codex-plugin/plugin.json

@@ -0,0 +1,23 @@
+{
+    "name": "kotlin-agent-skills",
+    "version": "1.0.0",
+    "description": "AI agent skills for Kotlin projects.",
+    "author": {
+        "name": "Kotlin",
+        "url": "https://kotlinlang.org/"
+    },
+    "homepage": "https://github.com/Kotlin/kotlin-agent-skills",
+    "repository": "https://github.com/Kotlin/kotlin-agent-skills",
+    "license": "Apache-2.0",
+    "keywords": ["kotlin"],
+    "interface": {
+        "displayName": "Kotlin skills for agents",
+        "shortDescription": "Reusable skills for software development using Kotlin.",
+        "longDescription": "Reusable skills for software development using Kotlin.",
+        "developerName": "JetBrains",
+        "category": "Productivity",
+        "capabilities": ["Read", "Write"],
+        "websiteURL": "https://kotlinlang.org/"
+    },
+    "skills": "./skills"
+}

README.md

@@ -45,6 +45,15 @@ See [npx skills](https://github.com/vercel-labs/skills) for more options.
 /plugin install kotlin-agent-skills@Kotlin
 ```
 
+### Codex
+
+In shell:
+```shell
+codex plugin marketplace add Kotlin/kotlin-agent-skills
+```
+
+Then inside `codex` invoke `/plugins`, search for `kotlin-agent-skills`, press 'Enter' and select 'Install plugin'.
+
 ### Manual installation
 
 Copy the desired skill folder from [skills](./skills) into the skills directory of your agent, for example: