- The bottom of the "List and Tuples" section may mislead the reader
into thinking that the `fst` and `snd` functions can be applied to any
tuple; it's worth mentioning that those functions only apply to pairs.
- The example demonstrating the use of the function-application operator
(`$`) in combination with the function-composition operator (`.`) seems a
bit contrived. For completeness, I've added an example that uses `$` alone.
- "If statements" and "case statements" are actually expressions, in
Haskell; I've replaced all occurences of the word "statement" appearing in
that context by the word "expression".
- Minor wording improvement (replaced "because" by a semicolon).
Since all the functions work with lists, calling them arrays is inaccurate. This commit also updates `myMap` function so that it works on an empty list as well as resolves ambiguity about `x` from comment.
