Further work on static side

PkmnLib.Static/Libraries/AbilityLibrary.cs

@@ -0,0 +1,34 @@
+using System.Diagnostics.CodeAnalysis;
+using PkmnLib.Static.Species;
+using PkmnLib.Static.Utils;
+
+namespace PkmnLib.Static.Libraries;
+
+/// <summary>
+/// The library for all abilities in the game.
+/// </summary>
+public interface IReadOnlyAbilityLibrary
+{
+    /// <summary>
+    /// Tries to get an ability from the library. Returns false if the ability is not found.
+    /// </summary>
+    bool TryGet(StringKey key, [MaybeNullWhen(false)] out IAbility value);
+
+    /// <summary>
+    /// Gets a random ability from the library.
+    /// </summary>
+    IAbility GetRandom(IRandom random);
+
+    /// <summary>
+    /// The amount of abilities in the library.
+    /// </summary>
+    int Count { get; }
+
+    /// <summary>
+    /// Whether the library is empty.
+    /// </summary>
+    bool IsEmpty { get; }
+}
+
+/// <inheritdoc cref="IReadOnlyAbilityLibrary"/>
+public class AbilityLibrary : DataLibrary<IAbility>, IReadOnlyAbilityLibrary;