added readme asset for quick overview on usage and functionality

Author: ThatAmuzak

Samples~/Readme.asset

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+%YAML 1.1
+%TAG !u! tag:unity3d.com,2011:
+--- !u!114 &11400000
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 0}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: fcf7219bab7fe46a1ad266029b2fee19, type: 3}
+  m_Name: Readme
+  m_EditorClassIdentifier:
+  title: How to use Unity Singleton
+  sections:
+  - heading: Example Usage
+    text:
+    - This is a quick demo on how to use the Unity Singleton Package
+    - 'To quickly test it out:'
+    - "\u2022 Go to the Scenes in this Samples folder"
+    - "\u2022 Add the scenes in the following order"
+    - "    \u2022 _Preload"
+    - "    \u2022 Main Menu"
+    - "\u2022 Then open the Scenes folder and edit the name parameter on the GameManager component attached to the GameManager object"
+    - "\u2022 Save and press play"
+    - "\u2022 The scene will change to the Main Menu, and the log will print out the name provided"
+  - heading: Functionality overview
+    text:
+    - Add using UnityCommunity.UnitySingleton; for using the classes
+    - "\u2022 Use Singleton<T> for plain C# classes"
+    - "\u2022 Use MonoSingleton<T> if you want a Scene-based singleton which is not persistent across scenes"
+    - "\u2022 Use PersistentMonoSingleton<T> if you want a Global and persistent singleton across scenes"

Samples~/SamplesGuideInfo/Scripts.meta

@@ -0,0 +1,166 @@
+// Copyright (c) Unity Technologies.
+// Based on the "URP TutorialInfo ReadmeEditor.cs" script included in URP template projects.
+//
+// Original asset by Unity Technologies. This version has been modified to display
+// a custom Readme.asset in the Inspector about how to use the Singletons package
+//
+// Modified by github.com/ThatAmuzak - 2025
+
+using UnityEngine;
+using UnityEditor;
+using System.IO;
+
+[CustomEditor(typeof(Readme))]
+public class ReadmeEditor : Editor
+{
+    static string s_ReadmeSourceDirectory = "Assets/Samples/Unity Singleton/3.0.0/Samples/SamplesGuideInfo";
+
+    const float k_Space = 8f;
+
+    static void RemoveTutorial()
+    {
+        if (EditorUtility.DisplayDialog("Remove Readme Assets",
+
+            $"All contents under {s_ReadmeSourceDirectory} will be removed, are you sure you want to proceed?",
+            "Proceed",
+            "Cancel"))
+        {
+            if (Directory.Exists(s_ReadmeSourceDirectory))
+            {
+                FileUtil.DeleteFileOrDirectory(s_ReadmeSourceDirectory);
+                FileUtil.DeleteFileOrDirectory(s_ReadmeSourceDirectory + ".meta");
+            }
+            else
+            {
+                Debug.Log($"Could not find the Readme folder at {s_ReadmeSourceDirectory}");
+            }
+
+            var readmeAsset = SelectReadme();
+            if (readmeAsset != null)
+            {
+                var path = AssetDatabase.GetAssetPath(readmeAsset);
+                FileUtil.DeleteFileOrDirectory(path + ".meta");
+                FileUtil.DeleteFileOrDirectory(path);
+            }
+
+            AssetDatabase.Refresh();
+        }
+    }
+
+    static Readme SelectReadme()
+    {
+        var ids = AssetDatabase.FindAssets("Readme t:Readme");
+        if (ids.Length == 1)
+        {
+            var readmeObject = AssetDatabase.LoadMainAssetAtPath(AssetDatabase.GUIDToAssetPath(ids[0]));
+
+            Selection.objects = new[] { readmeObject };
+
+            return (Readme)readmeObject;
+        }
+
+        Debug.Log("Couldn't find a readme");
+        return null;
+    }
+
+    protected override void OnHeaderGUI()
+    {
+        var readme = (Readme)target;
+        Init();
+
+        GUILayout.BeginHorizontal("In BigTitle");
+        {
+            GUILayout.Space(k_Space);
+            GUILayout.BeginVertical();
+            {
+
+                GUILayout.FlexibleSpace();
+                GUILayout.Label(readme.title, TitleStyle);
+                GUILayout.FlexibleSpace();
+            }
+            GUILayout.EndVertical();
+            GUILayout.FlexibleSpace();
+        }
+        GUILayout.EndHorizontal();
+    }
+
+    public override void OnInspectorGUI()
+    {
+        var readme = (Readme)target;
+        Init();
+        Rect rect;
+        foreach (var section in readme.sections)
+        {
+            GUILayout.Space(k_Space);
+            rect = EditorGUILayout.GetControlRect(false, 2 );
+            rect.height = 2;
+            EditorGUI.DrawRect(rect, new Color ( 0.5f,0.5f,0.5f, 1 ) );
+            GUILayout.Space(k_Space);
+
+            if (!string.IsNullOrEmpty(section.heading))
+            {
+                GUILayout.Label(section.heading, HeadingStyle);
+            }
+
+            foreach (var subtext in section.text)
+            {
+                if (!string.IsNullOrEmpty(subtext))
+                {
+                    GUILayout.Label(subtext, BodyStyle);
+                }
+            }
+        }
+        GUILayout.Space(k_Space);
+        rect = EditorGUILayout.GetControlRect(false, 2 );
+        rect.height = 2;
+        GUILayout.Space(k_Space);
+        if (GUILayout.Button("Remove Readme Assets", ButtonStyle))
+        {
+            RemoveTutorial();
+        }
+    }
+
+    bool m_Initialized;
+
+    GUIStyle TitleStyle => m_TitleStyle;
+
+    [SerializeField]
+    GUIStyle m_TitleStyle;
+
+    GUIStyle HeadingStyle => m_HeadingStyle;
+
+    [SerializeField]
+    GUIStyle m_HeadingStyle;
+
+    GUIStyle BodyStyle => m_BodyStyle;
+
+    [SerializeField]
+    GUIStyle m_BodyStyle;
+
+    GUIStyle ButtonStyle => m_ButtonStyle;
+
+    [SerializeField]
+    GUIStyle m_ButtonStyle;
+
+    void Init()
+    {
+        if (m_Initialized)
+            return;
+        m_BodyStyle = new GUIStyle(EditorStyles.label);
+        m_BodyStyle.wordWrap = true;
+        m_BodyStyle.fontSize = 14;
+        m_BodyStyle.richText = true;
+
+        m_TitleStyle = new GUIStyle(m_BodyStyle);
+        m_TitleStyle.fontSize = 26;
+
+        m_HeadingStyle = new GUIStyle(m_BodyStyle);
+        m_HeadingStyle.fontStyle = FontStyle.Bold;
+        m_HeadingStyle.fontSize = 18;
+
+        m_ButtonStyle = new GUIStyle(EditorStyles.miniButton);
+        m_ButtonStyle.fontStyle = FontStyle.Bold;
+
+        m_Initialized = true;
+    }
+}

Samples~/SamplesGuideInfo/Scripts/Editor.meta

@@ -0,0 +1,25 @@
+// Copyright (c) Unity Technologies.
+// Based on the "URP TutorialInfo ReadmeEditor.cs" script included in URP template projects.
+//
+// Original asset by Unity Technologies. This version has been modified to display
+// a custom Readme.asset in the Inspector about how to use the Singletons package
+//
+// Modified by ThatAmuzak - 2025
+
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+
+[CreateAssetMenu(fileName = "Readme", menuName = "ScriptableObjects/Readme", order = 1)]
+public class Readme : ScriptableObject
+{
+    public string title;
+    public Section[] sections;
+
+    [Serializable]
+    public class Section
+    {
+        public string heading;
+        public List<string> text;
+    }
+}