README.md Sentence structure improvement

[Script47]

Fixed the sentence structure to make it easier to read.

[Script47]

Definitely not, read how hard it is to say the original sentence:

It is very important that you should check the return value of password_hash prior to storing it, because false or null may be returned if it encountered an error.

You could possibly get away with the end change that I made but the should should not be be there. Compared to the sentence I proposed:

It is very important that you check the return value of password_hash prior to storing it, because false or null may be returned if it encountered an error.