add example for outputting legacy formats

Author: gregsdennis

_docs/schema/basics.md

@@ -263,7 +263,14 @@ No errors would actually be reported here because the output format defaults to
 
 ## Evaluation results {#schema-results}
 
-JSON Schema draft 2019-09 began the process to standardize the format for evaluation output in order to support cross-platform and cross-implementation compatibility.  The format has been updated for the upcoming release to be more concise and clear.  This includes support for both errors and annotation collection.
+JSON Schema draft 2019-09 began the process to standardize the format for evaluation output in order to support cross-platform and cross-implementation compatibility.
+
+For the next release of JSON Schema, these formats have been extracted into their own specification.  In addition, the formats themselves have been updated to increase clarity and readability.
+
+> More information on the changes can be found in [this blog post](https://json-schema.org/blog/posts/fixing-json-schema-output).
+{: .prompt-tip}
+
+_JsonSchema.Net_ supports the new, upcoming formats by default, however it can be configured for limited support of the specification requirements.  See [this example](/schema/examples/legacy-output) for more information.
 
 In summary, there are three levels of verbosity for output: Flag, List, and Hierarchy.
 
@@ -273,6 +280,9 @@ A list format reduces all of the errors to a flat list, housed in a top-level ob
 
 The hierarchical output format follows the structure of the schema.
 
+> The output formats can contain a lot of information you're probably going to end up ignoring (but can nevertheless be useful in some cases).  [This blog post](https://json-schema.org/blog/posts/interpreting-output) gives some examples and explanations of how to read JSON Schema output.
+{: .prompt-tip}
+
 The default output format is Flag, but this can be configured via the `EvaluationOptions.OutputFormat` property.
 
 > It's only possible to translate from a more detailed to a less detailed format.

_docs/schema/examples/legacy-output.md

@@ -0,0 +1,38 @@
+---
+layout: page
+title: Example - Serializing Output in the 2019-09 / 2020-12 Format
+bookmark: Legacy Output
+permalink: /schema/examples/:title/
+icon: fas fa-tag
+order: "01.4.5"
+---
+The 2019-09 and 2020-12 JSON Schema specifications define output formats that can be difficult to work with.
+
+For future versions of the specification, the output is undergoing some [changes](https://json-schema.org/blog/posts/fixing-json-schema-output).  This new format is the default for _JsonSchema.Net_, however the evaluation results can still be serialized to the 2019-09 / 2020-12 formats by using the `Pre202012EvaluationResultsJsonConverter`.
+
+```c#
+var schema = JsonSchema.FromText(" ... ");
+var options = new EvaluationOptions
+{
+    OutputFormat = OutputFormats.List
+};
+var instance = JsonNode.Parse(" ... ");
+var results = schema.Evaluate(instance, options);
+
+var serializerOptions = new JsonSerializerOptions
+{
+    Converters = { new Pre202012EvaluationResultsJsonConverter() }
+};
+var output = JsonSerializer.Serialize(results, serializationOptions);
+```
+
+The `OutputFormat` option still controls which format you'll get:
+
+| `OutputFormat` | "New" format (default) | "Legacy" format |
+|:-:|:-:|:-:|
+| `Flag` | flag | flag |
+| `List` | list | basic |
+| `Hierarchical` | hierarchical | verbose |
+
+> The "detailed" format defined by the specification is not supported since it requires some advanced logic (which was never properly specified) to pare down the nodes.
+{: .prompt-warning}