Remove obsolete doc section

`FromSql` / `ToSql` are now implemented for i64 and usize

src/types/from_sql.rs

@@ -76,16 +76,6 @@ impl Error for FromSqlError {
 pub type FromSqlResult<T> = Result<T, FromSqlError>;
 
 /// A trait for types that can be created from a SQLite value.
-///
-/// Note that `FromSql` and `ToSql` are defined for most integral types, but
-/// not `u64` or `usize`. This is intentional; SQLite returns integers as
-/// signed 64-bit values, which cannot fully represent the range of these
-/// types. Rusqlite would have to
-/// decide how to handle negative values: return an error or reinterpret as a
-/// very large postive numbers, neither of which
-/// is guaranteed to be correct for everyone. Callers can work around this by
-/// fetching values as i64 and then doing the interpretation themselves or by
-/// defining a newtype and implementing `FromSql`/`ToSql` for it.
 pub trait FromSql: Sized {
     /// Converts SQLite value into Rust value.
     fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self>;