Introduce a skeleton directory for hosting Claude plugins (#6656)

Motivation:

Recently, there was an agreement to host claude plugins with useful
features (skills/agents) that may aid in development using Armeria.
This PR introduces a basic skeleton directory, and a page on the armeria
site explaining the motivation.

Considerations:
- Plugins will be hosted in a separate directory within the repository -
independent from the site
- While it may be nice for documentation references to be embedded in
the skill, testing shows that Claude can read the documentation hosted
(although I assume each session will have to fetch newly if not in the
context already). This may be improved on later if necessary
- As installing the plugin is not very difficult, I don't think the
additional complexity of hosting the files separately on the website is
worth it. If there are any users interested, we may support later.
- A single common plugin is published for now
- While we may later consider publishing a plugin per-module, I think
it's simplest to start with a single plugin.
- All skills/agents aren't loaded in the context immediately from what I
understand
- If context consumption is a problem, maybe `disable-model-invocation`
can help

Modifications:

- Added a `marketplace.json` which contains the version/plugin
information
- Added a `Claude` related page under `Community` which describes how
the plugin may be used
- Created a skeleton directory for skills

Result:

- Closes #6639

<!--
Visit this URL to learn more about how to write a pull request
description:

https://armeria.dev/community/developer-guide#how-to-write-pull-request-description
-->

ref:
<img width="760" height="542" alt="스크린샷 2026-03-06 오전 11 22 50"
src="https://github.com/user-attachments/assets/7aa31b58-2f6c-4dcb-b65d-5e8baac8d620"
/>

Author: jrhee17

.claude-plugin/marketplace.json

@@ -0,0 +1,21 @@
+{
+  "name": "armeria",
+  "owner": {
+    "name": "armerian",
+    "email": "dl_armeria@linecorp.com"
+  },
+  "metadata": {
+    "description": "Claude plugin for the Armeria microservice framework",
+    "version": "0.0.1"
+  },
+  "plugins": [
+    {
+      "name": "assistant",
+      "source": {
+        "source": "git-subdir",
+        "url": "https://github.com/line/armeria.git",
+        "path": "tools/claude-plugins/assistant"
+      }
+    }
+  ]
+}

site-new/sidebarsCommunity.ts

@@ -7,6 +7,7 @@ const sidebars: SidebarsConfig = {
     'developer-guide',
     'code-of-conduct',
     'design-resources',
+    'claude-plugin',
   ],
 };
 

site-new/src/content/community/claude-plugin.mdx

@@ -0,0 +1,24 @@
+# Claude Plugin
+
+We maintain a [Claude](https://claude.ai/) plugin that may be useful for the community to use AI-powered guidance for development.
+
+## Installation
+
+You can install the Armeria Claude plugin from the marketplace:
+
+```bash
+/plugin marketplace add line/armeria
+/plugin install assistant@armeria
+```
+
+## Contributing
+
+To contribute new features to the Claude plugin:
+
+1. Create or update a markdown file in `<project dir>/tools/claude-plugins/assistant`
+2. Reference official Armeria documentation URLs if applicable
+3. Submit a pull request for review
+
+## References
+
+- [Claude Plugin Marketplaces Documentation](https://code.claude.com/docs/en/plugin-marketplaces)

site-new/src/content/community/index.mdx

@@ -38,6 +38,10 @@ Check out [the developer guide](/community/developer-guide) to learn how to buil
 
 We expect contributors to follow [our code of conduct](/community/code-of-conduct).
 
+## Using AI assistants? 🤖
+
+We provide a [Claude plugin](/community/claude-plugin) to help you work with Armeria more effectively using AI-powered assistance.
+
 ## Hall of fame 🏛️
 
 <ThankYou

tools/claude-plugins/assistant/.claude-plugin/plugin.json

@@ -0,0 +1,3 @@
+{
+  "name": "assistant"
+}