Remove some dead code

Turns out this was never needed.

CSF.Screenplay.Abstractions/IPerformableWithResult.cs

@@ -22,10 +22,6 @@ namespace CSF.Screenplay
     /// <see cref="IPerformableWithResult{TResult}"/>.
     /// </para>
     /// <para>
-    /// Objects which implement this interface may be adapted to <see cref="IPerformable"/> via the
-    /// <see cref="PerformableExtensions.ToPerformable(IPerformableWithResult)"/> extension method.
-    /// </para>
-    /// <para>
     /// When implementing this interface, consider also implementing <see cref="ICanReport"/>.
     /// If a performable does not implement <see cref="ICanReport"/> then it will receive default text when the
     /// <see cref="IPerformance"/> report is generated.
@@ -34,7 +30,6 @@ namespace CSF.Screenplay
     /// </remarks>
     /// <seealso cref="IPerformable"/>
     /// <seealso cref="IPerformableWithResult{TResult}"/>
-    /// <seealso cref="PerformableExtensions.ToPerformable(IPerformableWithResult)"/>
     public interface IPerformableWithResult
     {
         /// <summary>

CSF.Screenplay.Abstractions/IPerformableWithResult.generic.cs

@@ -20,12 +20,6 @@ namespace CSF.Screenplay
     /// If you do not wish to get a result from the performable then implement only <see cref="IPerformable"/> instead.
     /// </para>
     /// <para>
-    /// Objects which implement this interface may be adapted to <see cref="IPerformable"/> via the
-    /// <see cref="PerformableExtensions.ToPerformable{TResult}(IPerformableWithResult{TResult})"/> extension method or to
-    /// the non-generic <see cref="IPerformableWithResult"/> via
-    /// <see cref="PerformableExtensions.ToNonGenericPerformableWithResult{TResult}(IPerformableWithResult{TResult})"/>.
-    /// </para>
-    /// <para>
     /// When implementing this interface, consider also implementing <see cref="ICanReport"/>.
     /// If a performable does not implement <see cref="ICanReport"/> then it will receive default text when the
     /// <see cref="IPerformance"/> report is generated.
@@ -34,8 +28,6 @@ namespace CSF.Screenplay
     /// </remarks>
     /// <seealso cref="IPerformable"/>
     /// <seealso cref="IPerformableWithResult"/>
-    /// <seealso cref="PerformableExtensions.ToPerformable{TResult}(IPerformableWithResult{TResult})"/>
-    /// <seealso cref="PerformableExtensions.ToNonGenericPerformableWithResult{TResult}(IPerformableWithResult{TResult})"/>
     public interface IPerformableWithResult<TResult>
     {
         /// <summary>

CSF.Screenplay.Abstractions/PerformableExtensions.cs

@@ -6,56 +6,6 @@ namespace CSF.Screenplay
     /// <summary>Extension methods for performable types</summary>
     public static class PerformableExtensions
     {
-        /// <summary>
-        /// Gets an <see cref="IPerformable"/> which allows the specified performable (which returns a result) to be used
-        /// in a manner which discards its result.
-        /// </summary>
-        /// <remarks>
-        /// <para>
-        /// This is implemented by wrapping the performable in an adapter instance, so the object returned will not be the
-        /// original performable. It is not recommended to do so, but if the original performable is required then you may
-        /// cast this object to <see cref="NoResultPerformableAdapter"/> and use the
-        /// <see cref="NoResultPerformableAdapter.PerformableWithResult"/> property to get the original wrapped performable instance.
-        /// </para>
-        /// </remarks>
-        /// <param name="performableWithResult">The performable instance to be wrapped in an adapter</param>
-        public static IPerformable ToPerformable(this IPerformableWithResult performableWithResult)
-            => new NoResultPerformableAdapter(performableWithResult);
-
-        /// <summary>
-        /// Gets an <see cref="IPerformable"/> which allows the specified performable (which returns a generic result) to be used
-        /// non-generically and in a manner which discards its result.
-        /// </summary>
-        /// <remarks>
-        /// <para>
-        /// This is implemented by wrapping the performable in an adapter instance, so the object returned will not be the
-        /// original performable. It is not recommended to do so, but if the original performable is required then you may
-        /// cast this object to <see cref="NonGenericPerformableWithResultAdapter{TResult}"/> and use the
-        /// <see cref="NonGenericPerformableWithResultAdapter{TResult}.PerformableWithResult"/> property to get the original
-        /// wrapped performable instance. Of course, you will need to know &amp; use the correct generic type to do so.
-        /// </para>
-        /// </remarks>
-        /// <param name="performableWithResult">The performable instance to be wrapped in an adapter</param>
-        public static IPerformable ToPerformable<TResult>(this IPerformableWithResult<TResult> performableWithResult)
-            => new NonGenericNoResultPerformableAdapter<TResult>(performableWithResult);
-
-        /// <summary>
-        /// Gets an <see cref="IPerformableWithResult"/> which allows the specified generic performable to be used
-        /// non-generically.
-        /// </summary>
-        /// <remarks>
-        /// <para>
-        /// This is implemented by wrapping the performable in an adapter instance, so the object returned will not be the
-        /// original performable. It is not recommended to do so, but if the original performable is required then you may
-        /// cast this object to <see cref="NonGenericNoResultPerformableAdapter{TResult}"/> and use the
-        /// <see cref="NonGenericNoResultPerformableAdapter{TResult}.PerformableWithResult"/> property to get the original
-        /// wrapped performable instance. Of course, you will need to know &amp; use the correct generic type to do so.
-        /// </para>
-        /// </remarks>
-        /// <param name="performableWithResult">The performable instance to be wrapped in an adapter</param>
-        public static IPerformableWithResult ToNonGenericPerformableWithResult<TResult>(this IPerformableWithResult<TResult> performableWithResult)
-            => new NonGenericPerformableWithResultAdapter<TResult>(performableWithResult);
-
         /// <summary>Gets a report fragment for the specified performable and actor</summary>
         /// <remarks>
         /// <para>