Unhandled promise rejection when GitHub API query fails

[kholoud512]

Description:
Currently, if a GitHub API query fails (e.g., invalid project name, network error), the CLI throws an unhandled promise rejection or displays an unclear error.

We should catch all promise rejections and provide a friendly, descriptive error message to help the user understand the problem.

Steps to Reproduce:

1. Install the CLI globally: (npm i -g good-first-issue)
2. Run a query with a non-existent project: (good-first-issue thisisntarealprojectorgithuborg)

Expected Behavior:

• The CLI should display a clear error message:

Error: Unable to fetch issues for "thisisntarealprojectorgithuborg".
Please check the project name or your network connection.

• No unhandled promise rejection should appear.

Actual Behavior:
The CLI throws an unhandled promise rejection or crashes.

Environment:

• Node.js >= 8.0.0
• npm >= 5.0.0
• OS: Any

Project version: Latest from main branch

Proposed Solution (optional):

• Wrap all API calls in try/catch or use .catch() for promises.
• Add descriptive error messages for common failures (invalid project, network issues, rate limits).

[whoisrgxu]

Hi, I have experience working on developing CLI tool and fullstack projects. Could you please assign this issue to me? Thanks.