Added or Changed
> - Added five functions: truth-table generator and combinations, permutations, Bayes probability theorem, and time complexity calculator
> - truth-table generator: taking in an expression containing 2 variables (p and q), and prints a truth table. Supports the operations AND, NOT, and XOR.
> - combination and permutation calculator: taking in 2 inputs (n and r), and outputting either the combination or permutation.
> - Bayes probability theorem calculator: taking in 3 inputs (P(A|T),P(A), and P(T), and outputting the probability of P(T|A)
> - time complexity calculator: takes in 3 inputs(a, b, d), and outputs the correct time complexity function