Fix broken example in //> using dep reference doc (#3281)

Author: Gedochao

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

@@ -21,7 +21,7 @@ import scala.cli.commands.SpecificationLevel
 @DirectiveExamples("//> using test.dep org.scalatest::scalatest:3.2.10")
 @DirectiveExamples("//> using test.dep org.scalameta::munit:0.7.29")
 @DirectiveExamples(
-  "//> using dep tabby:tabby:0.2.3,url=https://github.com/bjornregnell/tabby/releases/download/v0.2.3/tabby_3-0.2.3.jar"
+  "//> using dep \"tabby:tabby:0.2.3,url=https://github.com/bjornregnell/tabby/releases/download/v0.2.3/tabby_3-0.2.3.jar\""
 )
 @DirectiveUsage(
   "//> using dep org:name:ver | //> using deps org:name:ver org2:name2:ver2",

website/docs/reference/directives.md

@@ -107,7 +107,7 @@ Add dependencies
 
 `//> using test.dep org.scalameta::munit:0.7.29`
 
-`//> using dep tabby:tabby:0.2.3,url=https://github.com/bjornregnell/tabby/releases/download/v0.2.3/tabby_3-0.2.3.jar`
+`//> using dep "tabby:tabby:0.2.3,url=https://github.com/bjornregnell/tabby/releases/download/v0.2.3/tabby_3-0.2.3.jar"`
 
 ### Exclude sources
 

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

@@ -48,7 +48,7 @@ Add dependencies
 
 `//> using test.dep org.scalameta::munit:0.7.29`
 
-`//> using dep tabby:tabby:0.2.3,url=https://github.com/bjornregnell/tabby/releases/download/v0.2.3/tabby_3-0.2.3.jar`
+`//> using dep "tabby:tabby:0.2.3,url=https://github.com/bjornregnell/tabby/releases/download/v0.2.3/tabby_3-0.2.3.jar"`
 
 ### Java options