Fix type of Creature referenceSources

This should have been Set<String> rather than Set<Source> since it is a unique collection of just the source name, without page references.

Author: keybuk

Sources/FifthEdition/Creature.swift

@@ -192,7 +192,7 @@ public struct Creature: Codable, Equatable, Sendable {
     public var sourceNote: String?
     public var page: Page?
     public var otherSources: Set<Source>?
-    public var referenceSources: Set<Source>?
+    public var referenceSources: Set<String>?
     public var additionalSources: Set<Source>?
     public var inSrd: SrdReference?
     public var inSrd52: SrdReference?

Tests/FifthEditionTests/Creature+CodableTests.swift

@@ -45,12 +45,7 @@ struct CreatureCodableTests {
                         "page": 38
                     }
                 ],
-                "referenceSources": [
-                    {
-                        "source": "XMM",
-                        "page": 42
-                    }
-                ],
+                "referenceSources": [ "XMM" ],
                 "size": [
                     "H"
                 ],
@@ -175,7 +170,7 @@ struct CreatureCodableTests {
                 source: "XMM",
                 page: .number(42),
                 otherSources: [.init(source: "MM", page: .number(38))],
-                referenceSources: [.init(source: "XMM", page: .number(42))],
+                referenceSources: ["XMM"],
                 size: [.huge],
                 type: .init(.type(.undead)),
                 alignment: .alignment([.chaotic, .evil]),