Use Scala 3-5-style Showable typeclass instead of Show

src/core/xmlast.scala

@@ -22,17 +22,17 @@ import gossamer.*
 import spectacular.*
 
 object XmlAst:
-  given Show[XmlAst] =
+  given XmlAst is Showable =
     case Comment(content)                       => t"<!--$content-->"
     case ProcessingInstruction(target, content) => t"<?$target $content?>"
     case Textual(content)                       => content
     case CData(content)                         => t"<![CDATA[$content]]>"
     case Root(content*)                         => t"""<?xml version = "1.0"?>${content.map(_.show).join}"""
-    
+
     case Element(name, children, attributes, _) =>
       val inside = children.map(_.show).join
       val attributeString = attributes.map { case (k, v) => t"${k.show}=$v" }.join(t" ", t" ", t"")
-      
+
       t"<${name.show}${attributeString}>$inside</${name.show}>"
 
 enum XmlAst:

src/core/xylophone.scala

@@ -31,7 +31,7 @@ import scala.util.NotGiven
 case class Namespace(id: Text, uri: Text)
 
 object XmlName:
-  given Show[XmlName] = name => name.namespace match
+  given XmlName is Showable = name => name.namespace match
     case Unset                => name.name
     case Namespace(prefix, _) => t"$prefix:${name.name}"
 
@@ -50,7 +50,7 @@ sealed trait Xml:
 type XmlPath = List[Text | Int | Unit]
 
 object Xml:
-  given show: Show[Xml] = xml =>
+  given Xml is Showable = xml =>
     safely(printers.compact.print(XmlDoc(XmlAst.Root(Xml.normalize(xml)*)))).or(t"undefined")
 
   given (using enc: Encoding, printer: XmlPrinter[Text]) => Xml is GenericHttpResponseStream: