$ cat << EOF >> passwords.txt
January
February
March
April
May
June
July
August
September
October
November
December
Autumn
Fall
Spring
Winter
Summer
password
Password
P@ssw0rd
secret
Secret
S3cret
EOF
Add year and exclamation point to the end of each password:
$ for i in $(cat passwords.txt); do echo "${i}"; echo "${i}\!"; echo "${i}2020"; echo "${i}2020\!"; done > t
$ cp t passwords.txt