Update time docs to reflect new chrono feature flag name

Changes `chrono` -> `chrono-04` to reflect the new name for the feature flag.

Author: willshiao

docs/source/data-types/time.md

@@ -42,7 +42,7 @@ while let Some((value,)) = iter.try_next().await? {
 
 ## chrono::NaiveTime
 
-If `chrono` feature is enabled, [`chrono::NaiveTime`](https://docs.rs/chrono/0.4/chrono/naive/struct.NaiveDate.html)
+If `chrono-04` feature is enabled, [`chrono::NaiveTime`](https://docs.rs/chrono/0.4/chrono/naive/struct.NaiveDate.html)
 can be used to interact with the database. Although chrono can represent leap seconds, they are not supported.
 Attempts to convert [`chrono::NaiveTime`](https://docs.rs/chrono/0.4/chrono/naive/struct.NaiveDate.html) with leap
 second to `CqlTime` or write it to the database will return an error.