Update peakdet contributors and contributions

[smoia]

@physiopy/all if there is any contributions or contributor we're not recognising, please let me know before this upcoming Sunday so that we can feature it in the ISMRM presentation. You can check again the emoji table here:
https://allcontributors.org/docs/en/emoji-key

[m-miedema]

It's probably good to take a moment here and figure out how the migration might have affected contributor recognition more generally!