chore: updating contribution guide

[Emmanuel-Tyty]

Thank you for contributing to Developer Experience Working Group. Please fill out the following template, selecting the sections that best suit your case, to assist us in reviewing your PR.

Description

This PR updates the contributions guide on how to approach contributions and completion timelines to be specific.

Related Issue

#119

Type of Change

Check the type of change this PR introduces:

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactor (improves code structure or readability without changing functionality)
• Other (please describe):

Changes Made

Contributing.md uodated

Checklist

Ensure you have completed the following steps before submitting your PR:

• My code follows the project's coding style and guidelines.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation (if applicable).
• My changes generate no new warnings or errors.
• I have added tests that prove my fix is effective or that my feature works.
• I have checked for merge conflicts.
• I have rebased my branch onto the latest main or master branch.