refactor: add doc to auth level (planning#2016)

client/src/main/java/dev/fitko/fitconnect/api/domain/zbp/message/AuthenticationLevel.java

@@ -3,10 +3,31 @@ package dev.fitko.fitconnect.api.domain.zbp.message;
 import com.fasterxml.jackson.annotation.JsonValue;
 import lombok.Getter;
 
+/**
+ * Representation of the STORK-QAA-Levels
+ */
 @Getter
 public enum AuthenticationLevel {
 
-    ONE(1), TWO(2), FOUR(4);
+    /**
+     * Basisregistrierung
+     */
+    ONE(1),
+
+    /**
+     * Niedrig
+     */
+    TWO(2),
+
+    /**
+     * Substantiell
+     */
+    THREE(3),
+
+    /**
+     * Hoch
+     */
+    FOUR(4);
 
     @JsonValue
     private final int level;