Add all missing docs

PkmnLib.Dynamic/Events/ExperienceGainEvent.cs

@@ -2,8 +2,12 @@ using PkmnLib.Dynamic.Models;
 
 namespace PkmnLib.Dynamic.Events;
 
+/// <summary>
+/// Represents an event that occurs when a Pokémon gains experience.
+/// </summary>
 public class ExperienceGainEvent : IEventData
 {
+    /// <inheritdoc cref="ExperienceGainEvent"/>
     public ExperienceGainEvent(IPokemon pokemon, uint previousExperience, uint newExperience)
     {
         Pokemon = pokemon;
@@ -11,8 +15,19 @@ public class ExperienceGainEvent : IEventData
         NewExperience = newExperience;
     }
 
+    /// <summary>
+    /// The Pokémon that gained experience.
+    /// </summary>
     public IPokemon Pokemon { get; set; }
+
+    /// <summary>
+    /// The amount of experience the Pokémon had before the gain.
+    /// </summary>
     public uint PreviousExperience { get; }
+
+    /// <summary>
+    /// The amount of experience the Pokémon has after the gain.
+    /// </summary>
     public uint NewExperience { get; }
 
     /// <inheritdoc />