Add all missing docs

PkmnLib.Static/Utils/EnumerableHelpers.cs

@@ -34,6 +34,9 @@ public static class EnumerableHelpers
         return -1;
     }
 
+    /// <summary>
+    /// Removes all elements from a list that match the given predicate.
+    /// </summary>
     public static void RemoveAll<T>(this IList<T> list, Func<T, bool> predicate)
     {
         for (var i = list.Count - 1; i >= 0; i--)