German translation - by @Marc-R2

[Marc-R2]

Add german translation de-de.json

[eibex]

Hi! Thanks for the PR.
There are a few errors that must be fixed before we can merge it. Discord has a character limit for both messages and modals (modals/cmd descriptions are particularly strict since they max out at 100 characters).
The following strings need to be fixed:
brief-settings-notify: must be 100 or less characters (now it's 148)
brief-settings-systemchannel: must be 100 or less characters (now it's 106)
message-reaction-option-channel: must be 100 or less characters (now it's 105)
message-reaction-option-action: must be 100 or less characters (now it's 105)
settings-systemchannel-option-type: must be 100 or less characters (now it's 112)
settings-activity-option-action: must be 100 or less characters (now it's 104)
settings-activity-option-activity: must be 100 or less characters (now it's 105)

[Marc-R2]

Oh, I didn't know that. I have corrected the mentioned lines.

[eibex]

Thanks!