Initial README update, rebase and amend this commit

README.md

@@ -1 +1,26 @@
-# DotTiled
+# 📚 DotTiled
+
+DotTiled is a simple, lightweight, and easy-to-use library for loading, saving, and managing Tiled maps and tilesets in your .NET projects. After [TiledCS](https://github.com/TheBoneJarmer/TiledCS) unfortunately became unmaintained (since 2022), I aimed to create a new library that could fill its shoes. DotTiled is the result of that effort.
+
+## Quickstart
+
+### Loading a map with external tilesets
+
+```csharp
+using DotTiled;
+
+TmxSerializer tmxSerializer;
+
+// Tiled can store tilesets in external files or in a map itself
+// When they are stored externally, you need to provide a way 
+// to resolve them given their source path
+Func<string, Tileset> externalTilesetResolver = (string path) => 
+{
+  // Load the tileset from however you want
+  var tilesetXml = fileSystem.ReadAllText(path);
+  var xmlStringReader = new StringReader(tilesetXml);  
+  var xmlReader = XmlReader.Create(xmlStringReader);
+  var tmxSerializer = tmxSerializer.DeserializeTileset(xmlReader);
+};
+
+```