arrange operations into folders in line with grouping from the specification and start creating a context to mutate through operations.

src/UglyToad.Pdf/Graphics/Operations/TextState/SetWordSpacing.cs

@@ -0,0 +1,21 @@
+namespace UglyToad.Pdf.Graphics.Operations.TextState
+{
+    internal class SetWordSpacing : IGraphicsStateOperation
+    {
+        public const string Symbol = "Tw";
+
+        public string Operator => Symbol;
+
+        public decimal Spacing { get; }
+
+        public SetWordSpacing(decimal spacing)
+        {
+            Spacing = spacing;
+        }
+
+        public override string ToString()
+        {
+            return $"{Spacing} {Symbol}";
+        }
+    }
+}