Filters an encrypted room keys export file to only include keys for the specified rooms. This allows you to share room keys for specific rooms with users who may have lost their keys.
The filtered file is written to filtered-KEY_FILE, where KEY_FILE is the name of the input file, and encrypted
using the same passphrase as the input file.
filter-keys KEY_FILE ROOM_ID [ROOM_ID...]For example:
filter-keys element-keys.txt '!roomid:example.org' '!roomid-2:example.org'