update README with link to tests and note about timezones on JS/Native

Author: bpholt

README.md

@@ -7,3 +7,17 @@ Parse Scala string literals into `java.time` instances at compile time.
 > duration"PT20.345S"
 val res0: java.time.Duration = PT20.345S
 ```
+
+See the [test suite for comprehensive examples](https://github.com/bpholt/java-time-literals/blob/main/core/shared/src/test/scala/dev/holt/javatime/JavaTimeSuite.scala)
+of all supported literal types.
+
+## Scala.js and Scala Native
+
+Since Scala.js and Scala Native don't have a built-in timezone database, if you need to use
+timezones other than UTC on those platforms, make sure to include
+
+```scala
+"io.github.cquiroz" %%% "scala-java-time-tzdb" % "2.5.0"
+```
+
+in your project dependencies.