Sample code errors

[jmin911]

Very good package.

There are some errors in the sample code.

.where(column("score") > 60 and (column("age") >= 20 or column("address").is_not_null()))

"and" should be &&, and "or" should be "||".

[janosimas]

This should not be an error, and and or are valid c++ keywords: https://en.cppreference.com/w/cpp/language/operator_alternative