Update ignore list

Signed-off-by: Michal Čihař <michal@cihar.com>
No need to explicitely ignore n/a

Signed-off-by: Michal Čihař <michal@cihar.com>
All week days

Signed-off-by: Michal Čihař <michal@cihar.com>
Ignore all two letter words in same check

Signed-off-by: Michal Čihař <michal@cihar.com>