Create README.md file for phpMyAdmin organization's profile

[MauricioFauth]

Is possible to add an overview for organization profiles now. We should add one for phpMyAdmin.

• Announcement: https://github.blog/changelog/2021-09-14-readmes-for-organization-profiles/
• PHP profile: https://github.com/php/.github/blob/master/profile/README.md
• Laminas profile: https://github.com/laminas/.github/blob/main/profile/README.md