(docs) show that Kotlin 2.0.21 is supported (#1883)

Author: wfouche

docs/modules/ROOT/pages/usage.adoc

@@ -190,9 +190,12 @@ As an experiment since 0.71.0 JBang supports building Kotlin files using `kotlin
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 jbang init -t hello.kt hello.kt
 ./hello.kt
-[jbang] Downloading Kotlin 1.5.0. Be patient, this can take several minutes...
-[jbang] Installing Kotlin 1.5.0...
-[jbang] Building jar...
+[jbang] Downloading Kotlin 2.0.21. Be patient, this can take several minutes...
+[jbang] Installing Kotlin 2.0.21...
+[jbang] Resolving dependencies...
+[jbang]    org.jetbrains.kotlin:kotlin-stdlib:2.0.21
+[jbang] Dependencies resolved
+[jbang] Building jar for hello.kt...
 Hello World
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