Add code owners

[sea212]

This PR adds code owners to this project. Code owners will be automatically selected as reviewers within PRs that modify parts of the project they own. Code owners are allowed to delegated their responsibility to review to someone else.

Initial code owners were determined by total involvement:

/node/ @sea212
/runtime/ @sea212
/zrml/authorized/ @Chralt98
/zrml/court/ @Chralt98
/zrml/global-disputes/ @Chralt98
/zrml/prediction-markets/ @maltekliemann
/zrml/rikiddo/ @sea212
/zrml/simple-disputes/ @Chralt98
/zrml/styx/ @yornaath
/zrml/swaps/ @maltekliemann

[maltekliemann]

When someone with admin or owner permissions has enabled required reviews, they also can optionally require approval from a code owner before the author can merge a pull request in the repository. For more information, see "About protected branches." [https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners]

Should we enable this?

[sea212]

When someone with admin or owner permissions has enabled required reviews, they also can optionally require approval from a code owner before the author can merge a pull request in the repository.
[...]

Should we enable this?

@maltekliemann I think this conflicts with the permission that the code owner can delegate the review, as the code owner will be forced to review by toggling this setting. I think it is sufficient that the code owner automatically gets notified as a reviewer in any PR, as the code owner will be aware when changes to parts of the code the code owners owns are requested to be applied. In case anyone just "wildly" merges PRs disregarding the code owners opinion at all, this will be definitely uncovered and discussed.

[codecov-commenter]

Codecov Report

Merging #1017 (544ce6f) into main (13f4e67) will not change coverage.
The diff coverage is n/a.

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@@           Coverage Diff           @@
##             main    #1017   +/-   ##
=======================================
  Coverage   94.46%   94.46%           
=======================================
  Files          93       93           
  Lines       21177    21177           
=======================================
  Hits        20004    20004           
  Misses       1173     1173           

Flag	Coverage Δ
tests	94.46% <ø> (ø)

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[yornaath]

🌮