Bug: github-mcp-server incorrectly uses local computer username as GitHub owner

## Description
The github-mcp-server incorrectly uses the local computer username as the GitHub repository owner when attempting to create issues or interact with GitHub repositories.

## Steps to Reproduce
1. Use Amazon Q CLI to create a GitHub issue
2. Observe that the tool automatically populates the "owner" parameter with the local computer username (e.g., "linuxmint-lp") instead of the actual GitHub username
3. The request fails because the owner is incorrect
4. Despite the failure, Amazon Q incorrectly reports success

## Expected Behavior
- The github-mcp-server should use the configured GitHub username or prompt for the correct owner
- Amazon Q should properly report failures when GitHub API calls fail
- Amazon Q should not falsely report success when operations fail

## Actual Behavior
- The github-mcp-server uses the local computer username as the GitHub owner parameter
- When corrected manually, Amazon Q takes the input literally even if misspelled
- Amazon Q reports success despite the operation failing

## Error Log
```
🛠️ Using tool: create_issue from mcp server github
⋮
● Running create_issue with the param:
⋮ {
⋮ "arguments": {
⋮ "body": "## Git MCP Server Configuration\n\n[content omitted for brevity]",
⋮ "owner": "linuxmint-lp", // This is incorrectly using local computer username
⋮ "repo": "dotfiles",
⋮ "title": "Add git-mcp-server configuration"
⋮ },
⋮ "name": "create_issue"
⋮ }
Allow this action? Use 't' to trust (always allow) this tool for the session. [y/n/t]:

> y

⋮
● Execution failed after 0.188s:
create_issue invocation failed to produce a result
```

## Environment
- OS: Linux (Linux Mint)
- Amazon Q CLI version: latest
- MCP server: github-mcp-server

## Proposed Solution
Update the AmazonQ.md documentation to include proper configuration for the github-mcp-server, specifically:

1. Add instructions for configuring the correct GitHub username
2. Document how to verify GitHub authentication is working properly
3. Add troubleshooting steps for common GitHub integration issues

## Additional Context
This issue causes confusion as Amazon Q incorrectly reports success despite operations failing. The tool should properly validate GitHub credentials and repository ownership before attempting operations.

Following our dotfiles philosophy of "spilled coffee" principle and automation mindset, we should ensure that the setup scripts properly configure the github-mcp-server with the correct GitHub credentials.

Open AmazonQ.md and compare its current GitHub MCP configuration guidance with the issue's create_issue example. Document how to configure the correct GitHub username, verify authentication, and troubleshoot failed GitHub operations; done means these steps are present and the documentation explains that failed calls should not be treated as successful.

Written by the indexing model from the issue text.