move Nemo157 to rustdoc alumni

[Nemo157]

I've been meaning to do this for a while as I haven't really been finding the time to contribute anymore.

cc @rust-lang/rustdoc

[github-actions]

Dry-run check results

[WARN  sync_team] sync-team is running in dry mode, no changes will be applied.
[INFO  sync_team] synchronizing github
[INFO  sync_team] 💻 Team Diffs:
    📝 Editing team 'rust-lang/all':
      Deleting member 'Nemo157'
    📝 Editing team 'rust-lang/rustdoc':
      Deleting member 'Nemo157'
    📝 Editing team 'rust-lang-nursery/rustdoc':
      Deleting member 'Nemo157'
    💻 Org membership Diffs:
    ❌ Removing the following members from `rust-lang`:
      - Nemo157
    ❌ Removing the following members from `rust-lang-nursery`:
      - Nemo157

[GuillaumeGomez]

It saddens me to see you go. Thanks a lot for your work all these years! Don't forget that if you find time and motivation, you are more than welcome to come back.