improve string distance documentation

src/commonMain/kotlin/com/infendro/cli/util/Distance.kt

@@ -3,7 +3,13 @@ package com.infendro.cli.util
 internal const val threshold = 2
 
 /**
- * Damerau-Levenshtein string distance
+ * Calculates the Damerau-Levenshtein distance between two strings.
+ *
+ * The distance is the minimum number of operations (insertion, deletion, substitution, and transposition) required to transform one string into another.
+ *
+ * @param a The source string.
+ * @param b The target string.
+ * @return The minimum number of operations to transform [a] into [b].
  */
 internal fun distance(a: String, b: String): Int {
     if (a == b) return 0