Explicitly call out that reuse is not implemented yet. (#173)

* Explicitly call out that reuse is not implemented yet.

* Fix incorrect Engine documentation

Co-authored-by: Luke Bordonaro <lukebo@microsoft.com>

Author: zachnew-msft

documentation/Using-the-SDK/Using-the-engine.md

@@ -39,13 +39,16 @@ processed by an `Engine` instance. The `DataSourceSet` will reference a
 `DataSourceSet` are able to be processed.
 
 ````cs
-using var plugins = PluginSet.Load();
-using var dataSources = DataSourceSet.Create(plugins);
-
-dataSources.AddDataSource(new FileDataSource("myfile.txt"));
-dataSources.AddDataSource(new FileDataSource("yourfile.txt"));
+using (var plugins = PluginSet.Load())
+{
+    using (var dataSources = DataSourceSet.Create(plugins))
+    {
+        dataSources.AddDataSource(new FileDataSource("myfile.txt"));
+        dataSources.AddDataSource(new FileDataSource("yourfile.txt"));
 
-// ... and so on
+        // ... and so on
+    }
+}
 
 ````
 
@@ -69,7 +72,7 @@ to pass `false` will be added in a future update.
 ````cs
 using (var plugins1 = PluginSet.Load())
 {
-    using (var dataSources = DataSourceSet.Create(plugins, true))
+    using (var dataSources = DataSourceSet.Create(plugins1, true))
     {
     }
 
@@ -82,9 +85,16 @@ using (var plugins1 = PluginSet.Load())
 In order to use the `Engine`, you must first load your plugins and data sources.
 Once you have done so, you may use the `Create` method with an `EngineCreateInfo`
 instance in order to create a useable `Engine.` Similar to how the `DataSourceSet`
-can take ownership of the `PluginSet`, the `Engine` takes ownership of the
-`DataSourceSet`. Set the `OwnsDataSources` property on the `EngineCreateInfo`
-instance to suppress this behavior.
+can take ownership of the `PluginSet`, the `Engine` can take ownership of
+data sources. The `Engine` will take ownership of and safely dispose of any
+`IDataSource` instances passed to its static `Create` methods. More concretely,
+an `Engine` created by calling either
+- `Create(IDataSource, Type)`
+- `Create(IEnumerable<IDataSource>, Type)`
+
+will take ownership of the data source(s) passed in as the first parameter. **To
+suppress this behavior, you must use the `Create(EngineCreateInfo)` method**.
+
 Once your `Engine` has been created, you can enable cookers and tables to
 participate in processing. If an attempt is made to enable a cooker for which
 there is no corresponding data source in the `DataSourceSet`, then an exception
@@ -108,3 +118,10 @@ using (var dataSources = DataSourceSet.Create(plugins))
 }
 ````
 
+# Reusing the DataSourceSet - Coming Soon
+
+We have plans for the future to enable reusing the `DataSourceSet` and `PluginSet`
+across `Engine` instances. However, this functionality has not been fully implemented.
+Thus, at this time, it is not supported to create a new `Engine` reusing a `DataSourceSet`.
+Once you have finished using an `Engine` instance, you should dispose the corresponding
+`DataSourceSet` and `PluginSet`