docs: document Scala Native flag options (#3557)

Author: scarf005

modules/directives/src/main/scala/scala/build/preprocessing/directives/ScalaNative.scala

@@ -10,11 +10,11 @@ import scala.cli.commands.SpecificationLevel
 @DirectiveExamples("//> using nativeVersion 0.4.0")
 @DirectiveUsage(
   "//> using nativeGc _value_ | using native-version _value_",
-  """`//> using nativeGc` _value_
+  """`//> using nativeGc` **immix**_|commix|boehm|none_
     |
-    |`//> using nativeMode` _value_
+    |`//> using nativeMode` **debug**_|release-fast|release-size|release-full_
     |
-    |`//> using nativeLto` _value_
+    |`//> using nativeLto` **none**_|full|thin_
     |
     |`//> using nativeVersion` _value_
     |

website/docs/reference/directives.md

@@ -337,11 +337,11 @@ Manually add a resource directory to the class path
 
 Add Scala Native options
 
-`//> using nativeGc` _value_
+`//> using nativeGc` **immix**_|commix|boehm|none_
 
-`//> using nativeMode` _value_
+`//> using nativeMode` **debug**_|release-fast|release-size|release-full_
 
-`//> using nativeLto` _value_
+`//> using nativeLto` **none**_|full|thin_
 
 `//> using nativeVersion` _value_
 

website/docs/reference/scala-command/directives.md

@@ -227,11 +227,11 @@ Manually add a resource directory to the class path
 
 Add Scala Native options
 
-`//> using nativeGc` _value_
+`//> using nativeGc` **immix**_|commix|boehm|none_
 
-`//> using nativeMode` _value_
+`//> using nativeMode` **debug**_|release-fast|release-size|release-full_
 
-`//> using nativeLto` _value_
+`//> using nativeLto` **none**_|full|thin_
 
 `//> using nativeVersion` _value_