Update the README.md

[CoachBirgit]

User Story or Initial Idea:
As a visitor or potential contributor to the #deib-working-group repository, I want a comprehensive overview of the project so that I can understand its purpose, goals, and how to get involved.

Issue Summary:
The repository requires a README.md file to provide essential information about the DEIB working group, its mission, and guidelines for participation.

Background & Context (The Why):
A README.md file serves as the first point of contact for anyone visiting the repository. It provides context, sets expectations, and guides visitors on how to engage with the project.

Acceptance Criteria:

• A detailed README.md file is present in the repository.
• The file provides an overview of the DEIB working group, its mission, goals, and contribution guidelines.

Proposed Steps or Tasks:

1. Outline the key sections for the README.md file.
2. Draft the content, providing details about the DEIB working group, its objectives, and how to contribute.
3. Review and gather feedback from the team.
4. Finalize and add the file to the repository.

Dependencies or Blockers:
None identified.

Additional Information:
Consider adding links to other important documents in the repository, such as the code_of_conduct.md and CONTRIBUTING.md files.

• Find further information on the mission and goals in the Proposal for Establishing a Make Diversity, Equity, Inclusion, and Belonging (“DEIB”) Team within the WordPress Community

Related Issues or Links:
None.

[CoachBirgit]

I copied the text, I've written on wp-deib.org as a starter for the README.md into a Google Doc.