Add missing reference docs for *.jar directives

Author: Gedochao

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

@@ -26,8 +26,16 @@ import scala.util.{Failure, Success, Try}
 @DirectiveUsage(
   "`//> using jar `_path_ | `//> using jars `_path1_ _path2_ …",
   """`//> using jar` _path_
-    |
     |`//> using jars` _path1_ _path2_ …
+    |
+    |`//> using test.jar` _path_
+    |`//> using test.jars` _path1_ _path2_ …
+    |
+    |`//> using source.jar` _path_
+    |`//> using source.jars` _path1_ _path2_ …
+    |
+    |`//> using test.source.jar` _path_
+    |`//> using test.source.jars` _path1_ _path2_ …
     |""".stripMargin
 )
 @DirectiveDescription("Manually add JAR(s) to the class path")

website/docs/reference/directives.md

@@ -67,9 +67,17 @@ Method used to compute the version for BuildInfo
 Manually add JAR(s) to the class path
 
 `//> using jar` _path_
-
 `//> using jars` _path1_ _path2_ …
 
+`//> using test.jar` _path_
+`//> using test.jars` _path1_ _path2_ …
+
+`//> using source.jar` _path_
+`//> using source.jars` _path1_ _path2_ …
+
+`//> using test.source.jar` _path_
+`//> using test.source.jars` _path1_ _path2_ …
+
 
 #### Examples
 `//> using jar /Users/alexandre/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/chuusai/shapeless_2.13/2.3.7/shapeless_2.13-2.3.7.jar`

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

@@ -125,9 +125,17 @@ Set the default Scala version
 Manually add JAR(s) to the class path
 
 `//> using jar` _path_
-
 `//> using jars` _path1_ _path2_ …
 
+`//> using test.jar` _path_
+`//> using test.jars` _path1_ _path2_ …
+
+`//> using source.jar` _path_
+`//> using source.jars` _path1_ _path2_ …
+
+`//> using test.source.jar` _path_
+`//> using test.source.jars` _path1_ _path2_ …
+
 
 #### Examples
 `//> using jar /Users/alexandre/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/chuusai/shapeless_2.13/2.3.7/shapeless_2.13-2.3.7.jar`