Adds more move scripts

Plugins/PkmnLib.Plugin.Gen7/Scripts/Moves/GrassTerrain.cs

@@ -0,0 +1,14 @@
+using PkmnLib.Plugin.Gen7.Scripts.Terrain;
+
+namespace PkmnLib.Plugin.Gen7.Scripts.Moves;
+
+[Script(ScriptCategory.Move, "grassy_terrain")]
+public class GrassyTerrain : Script
+{
+    /// <inheritdoc />
+    public override void OnSecondaryEffect(IExecutingMove move, IPokemon target, byte hit)
+    {
+        var battleData = move.User.BattleData;
+        battleData?.Battle.SetTerrain(ScriptUtils.ResolveName<Terrain.GrassyTerrain>());
+    }
+}