fix $76 add support for enum constants highlighting and initial enum documentation

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/annotators/LyngExternalAnnotator.kt

@@ -262,6 +262,18 @@ class LyngExternalAnnotator : ExternalAnnotator<LyngExternalAnnotator.Input, Lyn
             }
         }
 
+        // Map Enum constants from token highlighter to IDEA enum constant color
+        run {
+            val tokens = try { SimpleLyngHighlighter().highlight(text) } catch (_: Throwable) { emptyList() }
+            for (s in tokens) if (s.kind == HighlightKind.EnumConstant) {
+                val start = s.range.start
+                val end = s.range.endExclusive
+                if (start in 0..end && end <= text.length && start < end) {
+                    putRange(start, end, LyngHighlighterColors.ENUM_CONSTANT)
+                }
+            }
+        }
+
         // Build spell index payload: identifiers from symbols + references; comments/strings from simple highlighter
         val idRanges = mutableSetOf<IntRange>()
         try {

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/highlight/LyngColorSettingsPage.kt

@@ -65,6 +65,7 @@ class LyngColorSettingsPage : ColorSettingsPage {
         AttributesDescriptor("Type (semantic)", LyngHighlighterColors.TYPE),
         AttributesDescriptor("Namespace (semantic)", LyngHighlighterColors.NAMESPACE),
         AttributesDescriptor("Parameter (semantic)", LyngHighlighterColors.PARAMETER),
+        AttributesDescriptor("Enum constant (semantic)", LyngHighlighterColors.ENUM_CONSTANT),
     )
 
     override fun getColorDescriptors(): Array<ColorDescriptor> = ColorDescriptor.EMPTY_ARRAY

lyng-idea/src/main/kotlin/net/sergeych/lyng/idea/highlight/LyngHighlighterColors.kt

@@ -77,4 +77,9 @@ object LyngHighlighterColors {
     val ANNOTATION: TextAttributesKey = TextAttributesKey.createTextAttributesKey(
         "LYNG_ANNOTATION", DefaultLanguageHighlighterColors.METADATA
     )
+
+    // Enum constant (declaration or usage)
+    val ENUM_CONSTANT: TextAttributesKey = TextAttributesKey.createTextAttributesKey(
+        "LYNG_ENUM_CONSTANT", DefaultLanguageHighlighterColors.STATIC_FIELD
+    )
 }