Update faq.md - flip "confusion" and "convenience" in "is outweighed by" clause.

[wyattscarpenter]

A similar change to https://github.com/odin-lang/odin-lang.org/pull/206; this will be my final communication about this topic.

In my understanding, this paragraph is attempting to complain about implicit numeric type conversion in C. However, it currently implies it was a good thing in C, because of what it says outweighs what. This change flips the order.

This pr also makes two other slight corrections to enhance readability.