Add README and setup documentation for Greptile plugin

- Add README.md with setup instructions for getting API key
- Document the GREPTILE_API_KEY environment variable requirement
- Add homepage, author URL, and keywords to plugin.json
- Update description to reflect Greptile as AI code review agent

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: dakshgup

external_plugins/greptile/.claude-plugin/plugin.json

@@ -1,7 +1,10 @@
 {
   "name": "greptile",
-  "description": "AI-powered codebase search and understanding. Query your repositories using natural language to find relevant code, understand dependencies, and get contextual answers about your codebase architecture.",
+  "description": "AI code review agent for GitHub and GitLab. View and resolve Greptile's PR review comments directly from Claude Code.",
   "author": {
-    "name": "Greptile"
-  }
+    "name": "Greptile",
+    "url": "https://greptile.com"
+  },
+  "homepage": "https://greptile.com/docs",
+  "keywords": ["code-review", "pull-requests", "github", "gitlab", "ai"]
 }

external_plugins/greptile/README.md

@@ -0,0 +1,39 @@
+# Greptile
+
+[Greptile](https://greptile.com) is an AI code review agent for GitHub and GitLab that automatically reviews pull requests. This plugin connects Claude Code to your Greptile account, letting you view and resolve Greptile's review comments directly from your terminal.
+
+## Setup
+
+### 1. Create a Greptile Account
+
+Sign up at [greptile.com](https://greptile.com) and connect your GitHub or GitLab repositories.
+
+### 2. Get Your API Key
+
+1. Go to [API Settings](https://app.greptile.com/settings/api)
+2. Generate a new API key
+3. Copy the key
+
+### 3. Set Environment Variable
+
+Add to your shell profile (`.bashrc`, `.zshrc`, etc.):
+
+```bash
+export GREPTILE_API_KEY="your-api-key-here"
+```
+
+Then reload your shell or run `source ~/.zshrc`.
+
+## Capabilities
+
+Once configured, this plugin lets you:
+
+- **View Greptile review comments** - See what Greptile flagged on your PRs
+- **Resolve review comments** - Ask Claude Code to fix issues Greptile identified
+- **List pull requests** - View and filter PRs by repository, author, or status
+- **Trigger code reviews** - Request Greptile to review a PR
+- **Manage custom context** - Create and search organization-specific review rules
+
+## Documentation
+
+For more information, visit [greptile.com/docs](https://greptile.com/docs).