Add XML docs

StoneRed.LogicSimulator.Simulation/GateKind.cs

@@ -1,12 +1,46 @@
 namespace StoneRed.LogicSimulator.Simulation;
 
+/// <summary>
+/// Defines the types of logic gates available in the circuit simulator.
+/// </summary>
 public enum GateKind : byte
 {
+    /// <summary>
+    /// An input gate that can have its value set externally via <see cref="ICircuitSimulator.SetSource"/>.
+    /// Used as circuit inputs or constant values.
+    /// </summary>
     Source,
+
+    /// <summary>
+    /// A NOT gate that inverts its input (0 → 1, 1 → 0).
+    /// </summary>
     Not,
+
+    /// <summary>
+    /// A 2-input AND gate. Output is 1 only when both inputs are 1.
+    /// </summary>
     And2,
+
+    /// <summary>
+    /// A 2-input OR gate. Output is 1 when at least one input is 1.
+    /// </summary>
     Or2,
+
+    /// <summary>
+    /// A buffer gate that passes its input directly to the output.
+    /// Used for signal routing or as macro gate input pins.
+    /// </summary>
     Buffer,
+
+    /// <summary>
+    /// A sink gate that receives input but produces no useful output.
+    /// Used as circuit outputs or macro gate output pins.
+    /// </summary>
     Sink,
+
+    /// <summary>
+    /// A Look-Up Table gate implementing arbitrary combinational logic via a truth table.
+    /// Created using <see cref="ICircuitSimulator.AddLutGate"/> instead of <see cref="ICircuitSimulator.AddGate"/>.
+    /// </summary>
     Lut,
 }