Updates all copyright notices to include "Ghostty contributors" to
reflect the fact that Mitchell is not the sole copyright owner.
Also adds "Ghostty contributors" to the author section in the manpages,
linking https://github.com/ghostty-org/ghostty/graphs/contributors for
proper credit.
This reverts commit 14134d61fb, reversing
changes made to 6a876ef8ec.
This causes translation failures, this should be reintroduced when the
CI check passes.
Qwerasd