Dead Links on README.md

[SemicolonExpected]

There are some dead links on the README.md

Hack Night CSP Game
OSIRIS Wargames

Week 7 slides are missing and I cant find them
Week 12 slides on Kernal Exploits are missing

[ColdHeat]

Was this closed by #15 by chance?

[SemicolonExpected]

No, these are the links I couldnt fix