docs: update code owners

[mkbreuningIOHK]

Description:

• Code owners: the content editor will be automatically added to any PR related to markdown files
• Code owners: update by adding Todor Kolev (still not a member it seems though)

Checklist:

• My PR follows the contribution guidelines of this project
• [] My PR is free of third-party dependencies that don't comply with the Allowlist
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• [] I have added tests that prove my fix is effective or that my feature works
• I have checked the PR title to follow the conventional commit specification

[mkbreuningIOHK]

Need to add Todor to the IO organization