fix: remove duplicate documentation in plugins.md (#3764)

Remove duplicate documentation.

Co-authored-by: Odilitime <[email protected]>

docs/docs/core/plugins.md

@@ -302,46 +302,6 @@ packages/
   ],
 ```
 
-## Using Your Custom Plugins
-Plugins that are not in the official registry for ElizaOS can be used as well. Here's how:
-
-### Installation
-
-1. Upload the custom plugin to the packages folder:
-
-```
-packages/
-├─plugin-example/
-├── package.json
-├── tsconfig.json
-├── src/
-│   ├── index.ts        # Main plugin entry
-│   ├── actions/        # Custom actions
-│   ├── providers/      # Data providers
-│   ├── types.ts        # Type definitions
-│   └── environment.ts  # Configuration
-├── README.md
-└── LICENSE
-```
-
-2. Add the custom plugin to your project's dependencies in the agent's package.json:
-
-```json
-{
-  "dependencies": {
-    "@elizaos/plugin-example": "workspace:*"
-  }
-}
-```
-
-3. Import the custom plugin to your agent's character.json
-
-```json
-  "plugins": [
-    "@elizaos/plugin-example",
-  ],
-```
-
 ## FAQ
 
 ### What exactly is a plugin in ElizaOS?