KT-22815: Use gray color for filename

idea/src/org/jetbrains/kotlin/idea/KotlinQuickDocumentationProvider.kt

@@ -391,9 +391,9 @@ class KotlinQuickDocumentationProvider : AbstractDocumentationProvider() {
                         if (!fqName.isRoot) {
                             append(" ")
                         }
-                        append("(")
-                        append(fileName)
-                        append(")")
+                        wrap("<font color=\"808080\"><i>", "</i></font>") {
+                            append(fileName)
+                        }
                     }
                     if (fileName != null || !fqName.isRoot) {
                         append("<br>")

idea/src/org/jetbrains/kotlin/idea/kdoc/KDocRenderer.kt

@@ -166,7 +166,7 @@ object KDocRenderer {
     private fun renderTag(tag: KDocTag?, title: String, to: StringBuilder) {
         if (tag != null) {
             to.renderSection(title) {
-                markdownToHtml(tag.getContent())
+                append(markdownToHtml(tag.getContent()))
             }
         }
     }