Tool for Creating and Modifying GitHub Discussions via MCP Server

### Describe the feature or problem you’d like to solve

I would like to have a tool that can create (and possibly even modify) a discussion post. This would enable automation and integration for managing community discussions at scale, making it easier for LLMs and other systems to interact with participants in GitHub Discussions.

### Proposed solution

Adding this functionality would allow users and integrators to programmatically start or update Discussions directly from the MCP Server, making community engagement more efficient and consistent. It would also support large-scale and high-activity repositories by streamlining moderation and knowledge sharing. This would be especially beneficial for community-driven projects that rely heavily on Discussions as their primary collaboration space.

### Example prompts or workflows (for tools/toolsets only)

- "Create a new Discussion post in the repository with the following title and content."
- "Update the content of an existing Discussion post (by ID) to reflect new information."
- "Automatically post a summary of a weekly meeting as a Discussion post."
- "Moderate a Discussion by programmatically editing or closing posts based on flagged content."
- "Reply to an ongoing Discussion thread using an LLM-generated answer."

### Additional context

> @xcorail would it be useful to create an enhancement issue to track a `creatediscussion` functionality?

_Originally posted by @ericslandry in [#213](https://github.com/github/github-mcp-server/issues/213#issuecomment-3297890870)_