Add 4th sem CSE Notes

[NageshMandal]

1 Operating System 2 Design And Analysis Of Algorithms 3 Formal Language And Automata Theory 4 Discrete Mathematics 5 Database Management Systems

[Anushkabh]

I would like to contribute.. please assign it to me under gssoc'23 . @NageshMandal

[Anshika-Jain02]

@NageshMandal Sir, I would like to add some other semester notes. Can we create a new issue for this?

[DivyanshiNarang]

Hello @NageshMandal, I would also like to add other semester notes.

[NageshMandal]

@Anshika-Jain02 yes you can

[vk20july]

@NageshMandal sir can i do this task as the merge pr of this is not working?