[Feature]: Enhance text placement in relation to edges

# Description

Currently, the text rendering in `gh-skyline` places the text a little arbitrarily within the rendered elements. We want to improve this by placing the username and the year at a certain distance from their respective (left and right) edges

# Requirements

- Modify the text rendering logic to place the username a specified distance from the left edge.
- Place the year the same specified distance from the right edge.
- Ensure the distance is configurable through the `textRenderConfig` struct.
- Update any relevant documentation to reflect these changes.
- Write unit tests to verify the new text placement

# Definition of Done

- [ ] The username is placed a specified distance from the left edge.
- [ ] The year is placed the same specified distance from the right edge.
- [ ] The distance is configurable via `textRenderConfig`.
- [ ] Relevant documentation is updated.
- [ ] Unit tests are updated/written and passing.

# Additional Notes

- Follow standard Go conventions and best practices.
- Use clear, descriptive variable and function names.
- Add comments to explain complex logic or non-obvious implementations.
- Include GoDoc comments for all changes.

This issue is a great opportunity for new contributors to get familiar with the codebase and make a meaningful improvement. If you have any questions, feel free to ask!